

Hemmi
Slide Rule Catalogue Raisonné 

This Catalogue Raisonne describes every slide rule ever made by the Hemmi Slide Rule Company of Japanor at least all those I have been able to identify. It is the most comprehensive catalogue of Hemmi slide rules ever published. There are two parts: (1) This page lists Hemmi slide rules for which a model number is known. (2) The second page contains descriptions of Hemmimade slide rules for which I have not been able to determine a model number. They are usually rules with names rather than numbers or military rules or rules sold under another company's (Post, Foxboro, SKF, etc.) name. Construction material is celluloid on bamboo except for model number which begin with "P" (e.g., "P23") which are all plastic and for a few rules whose substance is explicitly mentioned in the text. This is an updated version of the Comprehensive Hemmi Catalog which was published in the Spring 2003 issue of the Journal of the Oughtred Society. It is based upon about 500 documents, photographs and specimen slide rules, many of which were supplied by my friends in Japan: William Lise, Atsushi Tomozawa, Yukio Kubota and Hitoshi Nori; I cannot begin to express my gratitude to them. Many errors exist in spite of their efforts and this catalog remains a work in progress. I will be grateful to anyone who can supply missing information or pictures or point out errors. I am indebted to Tom Dilatush for prolonged discussions of how this information should be organized and displayed. You may also be interested in A Hemmi Chronology. It lists the important dates and shows how markings on Hemmi rules changed from time to time.
Paul Ross, Feb 2022


Model 
Dates 
Front Scales 
Rear and Other
Calculating Scales 
Body 
Comment 
Also
Sold As 

Models118: Obsolete Model Numbers
Abandoned About 1930. 


1 1/1 
191329 
Pic 
A [B, C] D 
[S, L, T]

//Closed 250 x 28 x 9.5 mm 
Mannheim.
("Normal") Listed as obsolete starting
in 1936 but price listed in Hemmi catalogs through
1937 and available from Frederick Post (as model 1449)
through 1940. 
Tamaya 1941 (191627); HO 1768 (1914); Post 1449 (1930WWII) 
Pic 
Artillery
variant with minutes and mils conversion scales
on bottom edge and trigonometric formulas for gunnery
on back of rule. Dates probably later than model 1.


Pic 
A [B, Stadia, C] D 
Stadia variant.
Stadia scale (SinCos and Cos²) added to front of
slide. Dates probably later than model
1. 

2 
191329 
Pic 
Same as model 1 but with decimalindicating cursor.  //Closed 250 x 28 x 9.5 mm 
Discontinued ca1929.

Tamaya 1937 (191327); HO 1767 (191428) 

3 
191929 
Pic 
LL2, A [B, C] D, LL3 
[S, L, T] Gutter: E, F 
//Closed 250 mm x 1½ in x 10 mm 
Electro.
(Copy of Faber 378) LL scales keyed to offset W
gauge mark. E,F scales separated in gutter. No
overrange. HP gauge mark (probably only 746).
Single hairline. At least three different cursors. Tamaya
1905 (191927); HO 1770 (1928), Hemmi 80 (1930+). 

4 
191929 
Pic 
Same as 3
but with decimalindicating cursor. 
Tamaya 1904 (191627), Hemmi
81 (1930+ 

5 
191929 
Pic 
A [B, C] D 
[S, L, T] 
//Closed 500 mm x 1¼ x 13/32 in 
Listed as obsolete by Hemmi
in 1936 but price listed through 1937. In
Post catalog (model 1450) until WWII and in HO
catalog (model 1772) though1948. 
Tamaya 1899 (191627); HO 1772 (1928); Post 1450 (1936WWII). 
6 
191929 
Pic 
A [B, C] D 
[S, L, T] 
//Closed 125 x 24 x 9 mm 
Pocket Mannheim. Replaced by model 48 ca1930.  HO 1763 (191435); Tamaya 1942 (191627). 
7 
192629 
Pic 
Same as 6
but with decimalindicating cursor 
Tamaya 1949 (1927) 

8 
191329 
Pic 
A [B, C] D 
[S, L, T] 
/Closed 125 x 24 x 9 mm 
Extra Fine Mannheim w Magnifier.

Tamaya 1943 (191627); HO 1764 (191448) 
9 
191929 
Pic 
Same as 8
but with magnifiying decimalindicating cursor

Discontinued ca1929. 
Tamaya 1900 (191627) 

10 
192629 
Pic 
A [B, C] D 
[S, L, T] 
//Closed 250 mm 
Teninch extra fine with
"extended lens" magnifier. Discontinued ca1929. 
Tamaya 2148 (1927) 
11 
192629 
Pic 
Same as10
but with decimalindicating "extendedlens" cursor.

Discontinued ca1930. 
Tamaya 2180 (1927) 

12 
NA 
DF [CF, CI, C] D
(Folded at ?) 
Blank 
? 150 mm 
Simplified Slide Rule.
Plastic. Single uncorroborated reference. 

12 
192629 
Pic 
Same as model
3 but with "extendedlens" magnifying cursor. 
Discontinued ca1929. 
Tamaya 2782 (1927) 

13 
192629 
Pic 
Same as 4
but with decimalindicating "extendedlens" cursor. 
Discontinued ca1929.

Tamaya 2783 (1927) 

14 
192629 
Pic 
A [B, C] D 
[S, L, T] 
Closed 100 mm x 11/16 x 7/32 in 
Vest Pocket Mannheim with
square edges. 
Tamaya 2784 (1927); Hemmi 35 (1930+) 
15 
192629 
Pic 
Same as 14 but with decimalindicating
cursor. 
Discontinued ca1929. 
Tamaya 2785 (1927) 

16 
192629 
Pic 
Same as 14
but with magnifying cursor. 
Discontinued ca1929. 
Tamaya 2786. Hemmi 35ML (1930+) 

17 
192629 
Pic 
Same as 14
but with magnifying decimalindicating cursor. 
Discontinued ca1929. 
Tamaya 2787 

18 
182629 
Pocket kit including pen, pad and model 15 slide rule.  Discontinued ca1929.

Tamaya 2788 

19 
1927 
Pic 
A [B, C] D 
[S, L, T] ? 
250 mm 
Student version
of model 1. Model number may have been changed
to 40 before any were actually sold. 

Model Numbers 2024
were assigned to Classroom Demo Slide Rules before WWII;
Student Rules after WWII. 

20  193242 
NA 
A [B, CI, C] D, K 
[S, L, T] 
Demo 2000 mm 
Demonstration Mannheim (Model
50) 
Tamaya 4451 (1932) 
21 
193242 
NA 
K, A [B, CI, C] D, L
with overrange 
[S, S&T, T] 
Demo 2000 mm 
Demonstration Rietz (Model
64). 
Tamaya 4452 (1932) 
22 
195159 
Pic 
[CI, C] D, A 
No back 
Special 200 x 23 x 9 mm 
Cheap student
rule distributed in Asia only. Slide held to single
stator. Some (1955 only?) sandalwood, not bamboo.
Celluloid cursor. 

P23 
195769 
Pic 
A [B, CI, C] D 
A [B, CI, C] D 
Open 180 mm x 1 x 1/8 in 
Student Mannheim w CI scale. Hemmi's first plasticbased rule. 

24 
1927 
Pic 
A [B, C] D 
Blank 
//Closed 125 x 26 x 3 mm 
Ultrathin
all plastic with celluloid cursor.
13 cm scale on top edge; bottom blank. Identical
to model 34 except imprinted with advertising. Rare.
Appears in no known catalog. 

P24 
196369 
Pic 
DF [CF, CI, C] D, A Folded at √10. 
Blank 
Open 180 mm x 1 x 1/8 in 
Student. 

Models 3039: Miscellaneous Four and Fiveinch Closed Body Slide Rules  
30 
193043 
Pic 
A [B, C] D 
[S, L, T] 
//Closed 100 mm x 11/16 x 7/32 in 
Vest Pocket Mannheim. Model
number never appears on rule. Some w "SUN"
cut through or "SKF" embossed into backing
plate. 1000¥ ($2.78) in 1969. 
Tamaya 4453 (1927); Post 1447 (193133); Post 1440 (1934WWII) 
31 
193042 
Pic 
Same as 30 but
with decimalindicating cursor. 
No CI scale 
Tamaya 4454 

32 
193042 
Pic 
Same as 30 but with magnifying cursor.  Tamaya
4455; Post 1447M (193133); 1441 (1934WWII); Boston Blue Print 1441; US Blue 1888. 

33 
193042 
Pic 
Same as 30 but
with decimalindicating magnifying cursor 
No CI scale 
Tamaya 4456 

30R 
MIOJ1950 
Pic 
A [B, CI, C] D  [S, L, T]
(S keyed to A/B except WWII1955 keyed to C/D) 
//Closed 100 mm x 11/16 x 7/32 in 
Vest Pocket Mannheim w CI
scale. No model number on rule but case and box
marked "30R." 
Fuji 41. Post 1440. 
30 
1951EOB 
Pic 
Same
rule with "R" dropped from model number on case
and box. Allplastic cursor after ca 1970. 

32R 
MIOJ1950 
Pic 
Same
as 30R but with magnifying cursor 
Post 1441(WWII1971);
TP 44DA410 (1972+); HO 1760 (195264); Geo 3413405 (1964+) US Blue 1888 (MIOJ) 

32 
1951EOB 
Pic 
Same as 30
but with magnifying cursor. 

P33S 
1971 
Pic 
A [B, CI, C] D, K 
[S, L, T] (S keyed to C/D) 
Closed 125 x 28 x 5 mm 
Pocket Improved Mannheim.
Allplastic version of model 34RK. 

P33/SS 
1970 
Pic 
A [B, CI, C] D, K 
[S, L, T] (S keyed to C/D) 
Closed 125 x 27 x 4.5 mm 
Pocket Improved Mannheim.
Unique size. 
Geotec 3413610 
34 
1932 
Pic 
A [B, C] D 
Blank 
//Closed 125 x 26 x 3 mm 
Ultrathin all plastic with
celluloid cursor. 13 cm scale on top edge; bottom
blank 
Hemmi 24; Tamaya 4457 
34P 
193242 
NA 
A [B, C] D  Blank  //Closed 125 mm x 15/16 x 5/32 in 
Thin Pocket Mannheim with
blank back. 
Post 1443
(1931WWII) 
MIOJ 
Pic 
//Closed 125 x 26 x 5 mm 

34π 
193242 
Pic 
CF [DF,
CI, C] D Folded at π 
[S, L, T] (S keyed to C/D) 
//Closed 125 mm x 15/16 x 5/32 in 
Thin Pocket Mannheim with
folded scale. 
Post 1444
(c1935WWII); HO 1762 (1935WWII) 
MIOJ 
NA 
//Closed 125 x 26 x 5 mm 

34R 
193540 
Pic 
A [B, CI, C] D  [S, L, T] (S keyed to A/B except WWII1955 keyed to C/D) 
//Closed 125 mm x 15/16 x 1/8 in 
Thin Pocket Mannheim w CI
Scale. 
Post 1444
(c1935WWII); HO 1762 (1935WWII) 
195568  NA 
//Closed 125 x 26 x 5 mm 

34RK 
1936EOB 
Pic 
A [B, CI, C] D, K 
[S, L, T] (S keyed to A/B except WWII1955 keyed to C/D) 
//Closed 125 x 26 x 5 mm 
Post 1444K
(193770),1444(1971); TP 44DA440 (1972+); US Blue 1887 (1930s); HO 1762 (WWII64); Geo 3413425 (1964+). 

34T 
193642 
Pic 
A [B, C] D 
[S, L, T] 
//Closed 125 mm x 15/16 x 1/8 in 
Thin Pocket Mannheim. "SUN"
or ASEA embossed into backing plate. 

35 
193548 
Pic 
A [B, C] D 
[S, L, T] 
Closed
100 mm x 11/16 x 3/16
in 
Vest Pocket Mannheim with 4inch and 10cm measuring scales on square edges  Hemmi 14; Post 1437 (c1935WWII); HO 1761 (193548) 
35ML 
1930s 
Pic 
Same as 35 but with magnifying cursor  Hemmi
16 

P35 B35 
195961 
Pic 
K, DF [CF, CI, C] D, A Folded at √10. 
Blank 
Open 115 mm x 1 x 1/8 in 
Marked "B35"
(factory error for "P35"?); thin bamboo core
covered with PVC (not celluloid); scales printed
(not engraved). All known specimens also marked HO
1759. 

P35S 
1971 
Pic 
K, DF [CF, CI, C] D, A Folded at √10. 
[LL1, LL2, LL3] 
Closed 125 x 28 x 4.6 mm 

36 
1936WWII 
Pic 
A [B, CI,
C] D 
[S, L, T] 
Closed 125 mm x ¾ x 7/32 in 
Narrow Pocket Mannheim w
CI scale. Measuring scales on BACK of rule. 
Post 1438 (c1935WWII) 
P36 P36S 
196670 
Pic 
D [Conversion gauge marks,
A] D 
Instructions [Conversion gauge
marks, B] Instructions 
Open 115 mm x 1 x 1/8 in 
Rule is labeled "P36;" box and instructions "P36S." Set arrow on slide opposite value on top D scale; converted value appears on bottom D scale opposite corresponding arrow. Reverse slide for more conversions. Markings and instructions in Japanese. 450¥ ($1.25) in 1969.  
P37 
196670 
Pic 
(1), (2),
D [C, CI, B] MD1, MD2 
[B, PR1, PR2, PR3] 
Closed 125 x 28 x 4.6 mm 
SALES.
Labeled in Japanese. MD1 is months and days from 1/1
to 6/30, MD2 from 7/1 to 12/31. PR123 = three short
profit ratio scales. Reverse slide to read B, PR scales..
{Two hairlines: D: 1.2}. 700¥ ($1.94) 1969. 

P39 
NA 
K, A, DF [CF, CIF, CI,
C] D, DI, L Folded at ? 
[B, TI, SI, C] 
Closed 125 mm 
Single uncorroborated reference. 

Models 4049: Basic
Mannheim Rules (A [B, C] D) before WWI and
"Improved" Mannheim (A [B, CI, C] D, K) after WWII. 

40 
193249 
Pic 
A [B, C] D 
[S, L, T] 
Closed 250 x 28 x 8 mm 
Tamaya 4458
(1927), Post 1446 (193149); HO 1768 (193548);
Boston Blue Print 1446; US Blue 1876 (1930s); Lietz
2974N (1930s). 

41 
193242 
Pic 
A [B, C] D 
[S, L, T] 
Closed 125 mm 
Pocket Mannheim. No measuring scales  Tamaya 4459 (1932) 
42 
1932 
Pic 
A [B, C] D 
[S, L, T] 
Closed 250 x 28 x 8 mm 
Model 40 w measuring scales on BACK.  Tamaya 4460 (1932) 
43 
1932 
NA 
Same as 42 but
with decimalindicating cursor. 
Tamaya
4461 (1932) 

44 
1932 
Pic 
A [B, C] D 
[S, L, T] 
Closed 125 mm x 15/16 x ¼ in 
No slant; cm & inch scales on back of rule.  Tamaya 4462 (1932) 
45 
1932  NA 
Same as 44 but with decimalindicating cursor.  Tamaya
4463 (1932) 

45 
194968 
Pic 
DF [CF, CI, C] D, A Folded at √10. 
[TI, L, SI] 
Closed 200 x 28 x 8 mm 
Student. Quite different
from 1932 model 45. 

46 
193642 
Pic 
A [B, C] D 
Blank 
Special. 125 mm
x 1 in 
"Cardboard covered in transparent
celluloid with leather sheath." 

47 
193642 
Pic 
A [B, C] D 
[S, L, T] 
//Closed 250 x 28 x 8 mm 
Thin successor to model
1/1. 
Post 1449T (1937WWII) 
48 
193242 
Pic 
A [B, C] D 
[S, L, T] 
//Closed 125 mm x 15/16 x ¼ in 
Pocket Mannheim. Thin
successor to model 6. 

40F 
196869 
Pic 
K, DF [CF, CI, C] D, A Folded at √10 
[TI, L, SI] 
Closed 250 x 28 x 8 mm 
Fuji 85. 

40RK 
194969 
Pic 
A [B, CI,
C] D, K 
[S, L, T] (S keyed to A/B except Staedtler 94455 keyed to C/D) 
Closed 250 x 28 x 8 mm 
Improved
Mannheim. ("Slide Rule with CI and K Scale" in
early literature) 
Post 1447 (c19491971); HO 1768C (195264); Geo 3413526 (196471); US Blue 1877 (1940s?). 
1973 
Pic 
Same as preceding but wider with thick plastic back.  Closed 250 mm x 1¼ x 9/32 in 
TP 44BA470 (1972+); HO 3413526 (1972+) 

4050 
Pic 
Overhead projection rule for Hemmi model 40RK.  Projection 305
x 182 x 12 mm 

P 40RK 
196769 
Pic 
A [B, CI,
C] D, K 
[S, L, T] 
Open 250 x 28 x 8 mm 
AllPlastic Improved Mannheim.
Hard plastic case. 
Post 1447P (c1967); Geo 3413530 (c1967) 
43A 
196171 
Pic 
A [B, CI,
C] D, K 
[T, L, S] (S keyed to C/D) 
Closed 200 x 28 x 8 mm 
Student Improved Mannheim. 

P43D 
1973EOB 
Pic 
A [B, CI,
C] D, K 
[T, L, S] (S keyed to C/D) 
Closed 200 x 28 x 6.4 mm 
Like 43S except no indices
on back of rule; slide must be reversed. 

P43S 
1969 
Pic 
A [B, CI,
C] D, K 
[T, L, S] (S keyed to C/D) 
Closed 200 x 28 x 6.4 mm 
Plastic version of 43A.
Indices for reading trig scales on back of rule.


45K 
1962EOB 
Pic 
K, DF [CF, CI, C] D, A Folded at √10. 
[TI, L, SI] 
Closed 200 x 28 x 8 mm 
Post 1445
(c196671); TP 44BA450 (1972+); Geo 3413500 (1967+). All have scales folded at π. 

P45K 
196569 
Pic 
K, DF [CF, CI, C] D, A Folded at √10. 
[TI, L, SI] 
Open 200 x 28 x 5 mm 
Open body allplastic version
of 45K 
Post 1445P (1965)
Scales folded at π. 
P45D 
1973EOB 
Pic 
K, DF [CF, CI, C] D, A Folded at √10. 
[T, L, S] 
Closed 200 x 28 x 6.4 mm 
"Junior High
School Students." Like P45S except trig scales
not inverted and no indices on back of rule; slide
must be reversed. 

P45S 
196973 
Pic 
K, DF [CF, CI, C] D, A Folded at √10. 
[TI, L, SI] 
Closed 200 x 28 x 6.4 mm 
Closed body allplastic
version of 45K. Simpler construction than P45K. 

Models 5059: "Improved" Mannheim Slide Rules (A [B, CI, C] D, K and [S, L, T]) and Variants.  
50,
50/1, 50/3 
193251 
Pic 
A [B, CI,
C] D, K 
[S, L, T] (S keyed to A/B except WWII1955 keyed to C/D) 
//Closed 250 x 28 x 10.5 mm 
Improved Mannheim. Formerly
model 102. 
Hemmi 102; Tamaya 4464 (1932);
Post 1452 (c193551); HO 1771 (192848); US Blue 1880 (1930s). 
50F,
50/1F 
1936MIOJ 
Pic 
A [B, CI,
C] D, K 
[S, L, T] 
//Closed 250 x 28 x 8 mm 
Thin version of 50, 50/1
but accepts standard cursor. 
Post 1452T (1936WWII). 
50π/1 
193642 
Pic 
A, DF [CF, CI, C] D, L Folded at π. 
[S, S&T, T] 
//Closed 250 x 28 x 10.5 mm 
Post 1455 (c1935WWII). 

50W  1951EOB (For Post) 
Pic 
A [B, CI,
C] D, K 
[S, L, T] (S keyed to A/B except WWII1955 keyed to C/D) 
//Closed 250 x 34 x 11 mm 
Wide Improved Mannheim.

Post 1452W ('5170), 1452
('71); TP 44BA520 ('72+); HO 1771 ('5164); Geo 3413215 ('64+). 
P50 
1965?68? 
NA 
A [B, CI, C] D, K 
Blank 
Open? 250 mm x 1½ in 
Improved Mannheim. 

5020 
193548 
Pic 
A [B, CI, C] D, K 
[S, L, T]

//Closed 500 x 34 x 11 mm 
Long Improved Mannheim.
Made for Post & HO only; not sold as Hemmi
brand. 
Post 1454
(1936WWII); HO 1772 (193558) HO 3413235 (1969). 
WWII1969 
Pic 
//Closed 500 x 40 x 12 mm 
Wide Long Improved Mannheim.
Hemmi & Post brands. {Three Hairlines: D: C, C}. 

51/1,
51/3 
193242 
Pic 
Same as 50/1,
50/3 but with decimalindicating cursor. 
Formerly model 103.  Tamaya 4466, 4467 (1932). 

52 
193242 
Pic 
A [B, CI,
C] D 
[S, L, T] 
//Closed 125 mm x 15/16 x 11/32 in 
Thicker than
34R. 
Tamaya 4468; Post 1448 (193637). 
53 
193242 
Pic 
Same as 52 but
with decimalindicating cursor. 
Tamaya 4469 (1932). 

54 
193642 
Pic 
A [B, CI,
C] D, K with overrange 
[S, L, T] 
//Closed 150 x 26 x 6 mm 
"Extra Fine Improved Mannheim"
with magnifying cursor. 
Post 1453 (c1935WWII). 
55 
193642 
NA 
Same as 54 but
without magnifying cursor. 

Models 6079: Rietz Slide Rules ( K, A [B, C] D, L and [S, S&T, T] )  
60/1, 60/3 
19323x 
Pic 
K, A [B, C] D, L 
[S, S&T, T]

//Closed 250 mm x 1¼ x 13/32 in 
Rietz. Single line model 60/1 discontinued ca 1930.  Tamaya 4470,
4471 (1932) 
193x42 
Pic 
K, A [B, C] D, L with overrange 

61/3 
193242 
NA 
Same as 60/3
but with decimalindicating cursor. 

62/3 
1932 
NA 
K, A [B, C] D, L 
[S, S&T, T] 
//Closed 150 mm 
Extra Fine Rietz.  Tamaya 4472,
4473 (1932) 
63/3 
1932 
NA 
Same as 62/3
but with decimalindicating cursor. 

64,
64/1, 64/3 
193268 
Pic 
K, A [B, CI, C] D, L with overrange 
[S, S&T, T] 
//Closed 250 x 34 x 11 mm 
"System Rietz." {64/3 hairlines:
D: C, C} Some w 13013 cm on bottom. Probably
without overrange before 1935. 
Tamaya 4474 (1932) 
64T 
196571 
Pic 
K, A [B, BI, CI, C] D, DI, L with overrange 
[T2, T1, ST, S] 
//Closed 250 x 34 x 11 mm 
"Super Rietz." {3 hairlines: D: C, C}.  
65 
193242 
Pic 
Same as 64/3 but with decimalindicating cursor.  //Closed 250 x 34 x 11 mm 
Tamaya 4475 (1932) 

66 
193268 
Pic 
K, A [B, CI, C] D, L with overrange 
[S, S&T, T] 
//Closed 150 x 26 x 9 mm 
Extra Fine Improved Rietz.
{3line cursor: D: C, C} Some 808 cm on bottom. 
Tamaya 4476 (1932) 
66F 
193642 
Pic 
Same as 66 but
thin. 

67 
193242 
NA 
Same as 66 but
with 3line magnifying cursor.

Tamaya 4477 (1932) 

68 
193242 
NA 
Same as 66 but
with 3line decimalindicating cursor.

Tamaya 4478 (1932) 

69 
193242 
NA 
Same as 66 but
with 3line decimalindicating magnifying cursor.

Tamaya 4479 (1932) 

70  193243 
Pic 
K, A [B, CI, C] D, L some with overrange 
[S, S&T, T]  //Closed 500 x 34 x 12 mm 
Long Improved
Rietz. {3 hairlines: D: C, C}. 
Tamaya 4480 (1932) 
195170 
Pic 
//Closed 500 x 40 x 12 mm 

72 
196671 
Pic 
K, DF [CF,
CIF, CI, C] D, A with overrange Folded at √10. 
[TI2, TI1, L, SI] 
//Closed 500 x 40 x _ mm 
"Precision Slide Rule for
Practical Engineers." Single hairline. 

74 
1937EOB 
Pic 
K. A [B.
CI. C] D, L with overrange 
[S, S&T, T] 
//Closed 125 x 26 x 5 mm 
Pocket Improved Rietz.
{3 hairlines: D: C, C}. 

Models 8089: "Electro" Slide Rules  
80 80/1 80/3 
193032 
Pic 
LL2, A [B,
CI, C] D, LL3 No overrange 
No overrange [S, L, T] E, F widely separated in gutter. 
//Closed 250 mm x 1 ¼ in x 10 mm 
Electro. LL scales keyed to offset "W" gauge mark. No overrange. Same as model 3 with CI scale added.  Hemmi 3; Tamaya 4481, 4482 (1932); HO 1770 (1928c50); Post 1456 (c1934WWII) 
193233 
Pic 
//Closed 250 x 34 x 11 mm 
Same as preceding but on
slightly wider body. 

193436 
Pic 
[S, L, T]
E, F close together in gutter 
Same as preceding
but no "W" gauge mark. E, F close together
in gutter. 

193652 
Pic 
LL2, A [B, CI, C] D, LL3 with overrange 
Same as
preceding but with overrange extensions. 

81/1,
81/3 
193242 
Pic 
Same as 80/1, 80/3 but with decimalindicating cursor.  Details
vary depending upon date of manufacture. See
model 80. 
Hemmi 4; Tamaya 4482, 4484 (1932) 

82  193237 
NA 
Same as 80/1 except short.  //Closed 125 x _ x 9 mm 
Tamaya 4485 (1932) 

83 
193237 
NA 
Same as 82 but
with decimalindicating cursor. 
Tamaya 4486 (1932) 

84 
1932 
NA 
Same as 82 but
with magnifying cursor. 
Tamaya 4487 (1932) 

85 
1932 
Pic 
Same as 82 but with magnifying decimalindicating cursor.  Tamaya 4488 (1932) 

85 
MIOJ 
Pic 
db, Neper, A [B, CI, C] D 
[TI2, TI1, L, SI1] 
//Closed 250 x 34 x 11 mm 
Not electro, therefore model
number 85 is inappropriate. {3 hairlines: A: C^{2},
1.307} (Why 1.307?) 
Rare. 
80K 
195370 
Pic 
E, F, A [B, CI, C] D, LL2, LL3 with overrange 
[S, L, T] Bottom Edge: K 
//Closed 250 x 34 x 11 mm 
Electro.
K scale on bottom edge; no scales in gutter.
No hp mark but different cursors avail for British/US
and French/Metric HP. {3line cursor: A: hp, C^{2}}. 

86/3 
193642 
NA 
LL2, A [B, CI, C] D, LL3 with overrange 
[S, L, T] Gutter: E, F 
//Closed 150 x 26 x 8 mm 
"Extra fine Electro." Hp gauge
mark. No W mark. E,F scales close together in gutter.
{Three hairlines: A: hp, C^{2}}. 

87/3 
193642 
NA 
Same as 86/3
but with magnifying cursor. 

86/3K 
1950 
Pic 
LL2,
A [B, CI, C] D, LL3 with overrange 
[S, L, T]
Gutter: E, F Bottom Edge: K 
//Closed 150 x 26 x 8 mm 
Same as model 86/3 except
K scale added to bottom edge. 

86 
1951 
Identical to and contemporaneous
with model 86/3K. 

86K 
195470 
Pic 
E, F, A [B, CI, C] D, LL2, LL3 with overrange 
[S, L, T] Bottom Edge: K 
//Closed 150 x 26 x 8 mm 
"Extra Fine Electro." No
scales in gutter, no hp mark. {Three hairlines:
A: hp, C^{2}}. 

Models 9099: Stadia Slide Rules 

90 
193242 
Pic 
L, D [M1, M2, C] D, A with overrange  [S, S&T, T] Bottom Edge: K, IA 
//Closed 250 x 34 x _ mm 
Stadia. {3
hairlines: D: C, C}. Two calculating scales on
bottom edge. IA scale read from offset pointer keyed
to rightmost hairline. 

90A 
1940 
NA 
Same as 90 

90B 
1939? 
Pic 
Same as 90 but
uses "centesimal degrees." (100 centesimal degrees = right angle) 
First of a proposed series (models 90B, 91B, 2690B) of centesimaldegree stadia rules. Models 91B and 2690B were never manufactured.  
91 
193242 
Pic 
Same as 90 but
with decimalindicating cursor

Tamaya 4490 (1932) 

91A 
1939? 
NA 
Same as 91.  "91A" used to distinguish this rule
from proposed centesimal degree model 91B. 

92 
193242 
Pic 
L, D [M1, M2, C] D, A 
[S, S&T, T] Bottom Edge: K, IA 
//Closed 150 x 26 x 9.6 mm 
"Extra Fine Stadia." Two calculating scales on bottom edge. {3 hairlines: D: C, C}.  Tamaya 4491 (1932) 
93 
193242 
Pic 
Same as 92 but
with magnifying cursor. 
Tamaya 4491 (1932) 

94 
193242 
NA 
Same as 92 but
with decimalindicating cursor. 
Tamaya 4491 (1932) 

95 
193242 
NA 
Same as 92 but
with decimalindicating magnifying cursor 
Tamaya 4491 (1932) 

96 
193643 
Pic 
L, D [M1, M2, C] D, A with overrange. 
[S, S&T, T] Bottom Edge: K, IA 
//Closed 500 x 34 x 11 mm 
Long version of model 90. {3 hairlines: D: C, C}. Two calculating scales on bottom edge. IA scale read from offset pointer keyed to center hairline.  
Model Numbers 100107
were assigned to new rules developed in 192627; all
were replaced by modern numbering system about
1930. 

100 
192627 
Pic 
A [B, CI, C] D 
[S, L, T] 
//Closed 250 mm 
Short lived. 
Tamaya 2790 (1927) 
101 
192627 
Pic 
Same as 100
but with decimal indicating cursor.

Tamaya 2791 (1927) 

102 
192628 
Pic 
A [B, CI,
C] D, K 
[S, L, T] 
//Closed 250 x 28 mm 
Improved Mannheim. Model
number changed to 50/1 ca 1928. 
Tamaya 2792 (1927), HO1771 
103 
192628 
Pic 
Same as 102
but with decimalindicating cursor. 
Model
number changed to 51/1 ca 1928. 
Tamaya 2793, (1927) 

104 
1927 
Pic 
LL2, A [B, CI, C] D, LL3 No overrange 
[S, L, T] Gutter: E, F 
//Closed 125 mm 
"Pocket Electro." LL scales keyed to offset W gauge mark. E,F scales separated in gutter. No overrange. Hp gauge mark.  Hemmi 82; Tamaya 2994 (1927) 
105 
1927 
Pic 
Same as 104 but with decimalindicating cursor.  Hemmi
83, Tamaya 2995 

106 
1927 
NA 
Same as 104
but with magnifying cursor. 
Hemmi 84, Tamaya 2996 

107 
1927 
NA 
Same as 104
but with magnifying decimalindicating cursor. 
Hemmi 85, Tamaya 2997 

Models 100109: Large Classroom Demonstration Slide Rules  
100 
195168 
Pic 
DF [CF, CI, C] D, A Folded at √10. 
[TI, L,
SI] 
Demo 1000 mm 
Demonstration version of
model 45. 

100K 
196971 
Pic 
K, DF [CF,CI,
C] D, A Folded at √10 
[TI, L,
SI] 
Demo 1000 mm 
Demonstration version of
model 45K 

101 
195168 
NA 
ℓ, A [B, CI, C] D 
[S, K, T] (S keyed to C/D) 
Demo 1000 mm 
Demonstration version of
model 2640. 

101A 
1967EOB  Pic 
A [B, CI,
C] D, K 
[S, L, T] (S keyed to C/D) 
Demo 1000 mm 
Demonstration version of
models 40RK & 43A. 

102 
195468 
Pic 
CI, C, [D, A] 
Blank 
Demo 1000 mm 
Demonstration version of
model 22. 

103 
1959EOB 
NA 
K, DF [CF, CIF, CI, C]
D, A Folded at √10. 
[TI1, TI2, L, SI] 
Demo 1500 mm 
Demonstration version of
model 2664S. 

104 
195969 
NA 
Demo 1000 mm 
Demonstration. 

107 
1969EOB 
NA 
LL3, LL2, DF [CF, CIF,
CI, C] D, L, LL1 Folded at √10. 
K, A [B, TI1, TI2, SI] D, DI 
Demo 1000 mm 
Demonstration version of
model P253. 

108 
1971? 
NA 
LL/1, LL/2, LL/3, DF [CF,
CIF, CI, C] D, LL3, LL2, LL1 Folded at √10 
K, A [B, TI, SI, C] D, DI, L 
Demo 1000 mm 
Demonstration version of
model 254W. 

Models 110129: Specialty Slide Rules 

110 
1937MIOJ 
Pic 
LL2, A [B, CI, C] D, LL3 with overrange 
[S, S&T, T] Bottom Edge: K 
//Closed 250 x 34 x 11 mm 
Mechanical /Electrical slide
rule. K scale on bottom edge. {Three hairlines:
D: C, C}. 

120 
1939? 
Pic 
L, K, A [B, CI, S_{1}, T_{1},
C] D, S_{Θ} with overrange 
[LL3, LL3,
LL2, LL2, LL1,
LL1] Bottom Edge: G_{Θ} (2 scales) 
//Closed 250 x 34 x 11 mm 
"MIGHT." Listed
without description by Katsunori Kadokura
(Chronology of Japanese Hemmi Slide Rules, Journal
of the Oughtred Soc, Vol 1, No 2, August 1992). Pictured
specimen identified as Model 120 by Yukio Kubota, March 2014. 

DP121 
196869 
Pic 
LL3, LL2, DF [CF, CIF, CI, C] D, L,
LL1 
K, A [B, TI_{2}, TI_{1},
SI] D, DI 
Projection
305 x 182 x 12 mm 
Overhead projection rule
for model P253. Sold with five masks for obscuring
irrelevant scales. 
¥10,000 in catalog dated
6911 
DP122 
196869 
Pic 
K, A, DF [CF, CIF, CI]
D, DI, L 
K, A, DF [B, TI_{2}, TI_{1},
SI, C] D, DI, L 
Projection 305 x
182 x 12 mm 
Overhead projection rule
for models 2662 and 2664S. Sold with five masks for
obscuring irrelevant scales. 

Models 130139: Darmstadt Slide Rules
(L, K, A [B, CI, C] D, Cos, Sin, Tg and [LL1, LL2,
LL3]) and Variants 

130 
195069 
Pic 
L, K, A [B, CI, C] D, Cos with overrange 
[LL1, LL2, LL3] Bottom Edge: SIN, tg 
//Closed 250 x 34 x 11 mm 
Darmstadt. S and T scales
on bottom edge of rule. {3 hairlines: D: hpC, C}. 

130W 
197072 
Pic 
T, K, A [B, BI, CI, C]
D, P, S with overrange 
[L, LL0, LL1, LL2, LL3] 
//Closed 250 mm x 1½ x 7/16 in 
Advanced Darmstadt. Unique
width. {3 hairlines: A: C^{2}, hpC^{2}}. 

135 
195971 
Pic 
T, K, A [B, CI, C] D, P, S with overrange 
[L, LL1, LL2, LL3] 
//Closed 125 x 26 x 5 mm 
Pocket Darmstadt. {3 hairlines: D: hpC, C}. 

P135k 
2005 
Pic 
T, K, A [B, CI, C] D, P, S with overrange 
[L, LL1, LL2, LL3] 
Closed 200 x 32 x 4.3mm 
Darmstadt.
Only 250 made. Manufactured by HEMMI in 2005 to
specifications of ISRG and Japanese collectors
and sold by subscription. 

136 
195168 
Pic 
L, K, A [B, CI, C] D Cos with overrange 
LL1, LL2, LL3] Bottom Edge: SIN, tg 
//Closed 150 x 26 x 8 mm 
Extra Fine Darmstadt. D scale
is labeled "SIN" other scales not labeled. 

Models 140149: Pocket Duplex Slide Rules 

140 
MIOJ 
Pic 
DF [CF, CI, C] D, L Folded at √10. 
K, A [B, TI, SI, C] D, DI 
Duplex 150 mm x 1 3/16 x ¼ in 
Hemmi's first "pocket" duplex.
Body is short version of old narrow model 150.


141 P141 
1960EOB 
Pic 
LL/1, LL/2,
LL/3, DF [CF, CIF,
CI, C] D, LL3, LL2, LL1 Folded at π 
T, S, U, P [Q, c, V, R]
A q, n, L 
Duplex 125 x 34 x 4 mm 
Air conditioning
duct design. Bamboo (141) and allplastic
(P141) versions. Same blank as 149. Allplastic
version marked "'Carrier' Ductuler" (Toyo Carrier
Corp). Some bamboo specimens carry no brand name, some
marked "Carrier 50210," others marked "Shin Nippon
Kucho." (SNK was spun off from Toyo Carrier in 1969.)


143 
196869 
Pic 
P_{1}, P_{2},
DF [CF, CIF, CI, C]
D, LL (2 scales) Folded at 360. 
A, N [M, £, S/d, C] D, G  Duplex 125 x 34 x 4 mm 
"Commerce." N, M have 365
division for dates. £, S/d = pound/ shilling/ pence.
G is a set of conversion gauge marks. 
Pocket version of model
P263. 
149 
19591962 
Pic 
LL/1. LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π. 
L, K, A [B, TI, SI, C] D, LL0, LL/0  Duplex 125 x 34 x 4 mm 
"Pocket 259D"
but actually closer to 259 with TI, SI instead of T, S, ST.
Hemmi name on back of rule. Bare bamboo edges. 

149A 
1962EOB 
Pic 
Same as 149 except
celluloid veneer covers edges. 

P149A 
1976 
Pic 
LL/1, LL/2,
LL/3, DF [CF, CIF, CI, C]
D, LL3, LL2, LL1 Folded at π. 
L, K, A [B, TI, SI, C] D, LL0,
LL/0 
Duplex 125 x 36 x 4 mm 
All plastic. About 10 mm longer
overall and 2 mm wider than bamboo 149A.


Models
150300: Ten and TwentyInch Duplex and Open
Body Slide Rules 

150 
1925?1932? 
Pic 
DF [CF,
CIF, C] D Folded at π. 
K, A [B, S, T,
CI] D, L 
Duplex 250 mm x 1 3/16 x ¼ in 
Hemmi's first duplex slide
rule. (But Hemmi called models 150, 152, 153
and 154 "Universal," not "duplex.") Copied from K&E
40883 whose size it exactly duplicates. 
Post 1458 (1931) Lietz 3054L (before 1932) 
1932?MIOJ 
Pic 
Duplex 250 mm x 1 5/8 x ¼ in 
Standard (15/8 inch) width.
Replaced by model 250. 
Tamaya 4497 (1932) Post 1458 (1932WWII) US Blue 1881 (1937) H O 1765 (1935MIOJ) 

152 
192548 
Pic 
K, A [B, CI, C] D, T 
Θ, R_{θ}, P [Q, Q', C] LL3, LL2, LL1 
Duplex 250 mm x 1 5/8 x ¼ in 
"Electrical Engineer's Universal"
(Duplex). Often no model number. Some marked "US
Pat 1459857." (Patent issued to O D Parsons in
1923 for P, Q scales.) 
Tamaya 4498 (1932); Post
1459 (c1933WWII); HO 1766 (193548); US Blue 1889
(1930s) Lietz (1930s) 
153 
1931EOB 
Pic 
L, K, A [B, CI, C] D, T, G_{θ} 
Θ, R_{θ}, P, [Q, Q', C]
LL3, LL2, LL1 
Duplex 250 mm x 1 5/8 x ¼ in 
"Electrical Engineer's Universal"
(Duplex). Some (c1938) with stator screws on
back of rule. US Patent 2079464, May 4, 1937. 
Post 1461 (c1933WWII); US Blue 1893 (1030s) 
154 
192569 
Pic 
DF, P', P [Q, CF, CI, S_{θ}^{o}] A,
D, K Folded at π. 
Sχ, Tχ, T_{θ}^{o} [Th,
Sh, Sh, C] D, L, χ 
Duplex 500 mm x 1¾ x ¼ in 
Electrical Engineer's Universal
(Duplex) 20". Two cursors. Early production
has scale letters eteched on cursor windows.

Tamaya 4499 (1932); Post 1460 (c1933WWII) 
155 
WWII1951 
Pic 
K, A, DF [CF, B, CI, C] D, L Folded at √10. 
Sh_{1}, Sh_{2}, Th_{1}
[TI_{2}, TI_{1}, SI_{1},
C] D, DI 
Duplex 250 mm x 1 5/8 x ¼ in 
"General Engineering with
Hyperbolic Scales. " Replaced by model 255. 

157 
WWII1950 
Pic 
K, A, DF [CF, B, CI, C] D, L Folded at √10. 
LL/1, LL/2, LL/3 [TI_{2},
TI_{1}, SI_{1}, C] LL3, LL2, LL1

Duplex 250 mm x 1 5/8 x ¼ in 
"General Engineering with
LogLog Scales." 

159 
194952 
Pic 
T, DF [CF, CIF, CI, C] D, S, ST Folded at π 
LL0, LL00,
A [B, K, L, C] LL3, LL2, LL1 
Duplex 250 mm x 1 5/8 x ¼ in 
Made to specification of
F Post Co. Replaced by model 259 ("Expert Mechanical Engineer")
c1952. 
Post 1462H "POSTRIG" (c1949  53) 
160 
1951 
Pic 
Nomogram1(α=0.05), χ2,
A [B, CI, C] D, φ, ax 
P, F'1 [F'2, a'] A, χ2, ,Nomogram2(α=0.01) 
Duplex 250 mm x 72.5 mm 
"Inductive
Statistics." Almost three inches wide! Stator with
nomograms is about 46 mm wide. Allplastic cursor similar
to Relay/Ricoh. 

165 
1953 
Pic 
"Statistical
Sampling." No slide, just many short scales and
a cursor. 

190 
193942 
Pic 
K, A [B, R2, R1, C] D, DI 
[SI2, SCI2,
SI1, SCI1] Bottom Edge: L 
Closed 250 x 40 x 11 mm 
"Precision
Stadia." {3 hairlines: D: C, C}. Left half of SCI1 scale is inverse cos^{2}. 

200 
193668 
Pic 
D6, D5, D4 [C6, C5, C4,
C3, C2, C1] D3, D2, D1 
DF6, DF5, DF4 [CF6, CF5, CF4, CF3,
CF2, CF1] DF3, DF2, DF1 Scales divided at ^{6}√10. 
Duplex 400 mm x 1¾ x ¼ in 
"Precision Duplex." (Originally known as "Ultra Accuracy.") Four digit precision. Scales are divided into six segments, each 400 mm long. Early production has scale labels in green on cursor. U S Patent 2235106A, March 18, 1941.  
201 
196769 
Pic 
L2.4, L1.3, A2.4, A1.3
[C4, C3, C2, C1] D1, D2, D3, D4 
K4, K3, K2, K1 [CF4, CF3, CF2, CF1]
DF1, DF2, DF3, DF4 Scales divided at ^{4}√10. 
Duplex 500 mm x 1¾ x ¼ in 
"Sold in Japan." Scales are divided into four segments each 500 mm long. Early production has scale labels in green on cursor.  
250 
1950EOB 
Pic 
DF [CF, CIF, CI, C] D, L Folded at √10. 
K, A [B, TI_{2}, TI_{1},
SI] D, DI 
Duplex 250 mm x 1 5/8 x ¼ in 
"General Engineering and
Business." Replaced models 150 and 2600. About
a third have anodized black end brackets. 

251 
195158 
Pic 
L, DF [CF, CIF, CI, C] D, DI Folded at π. 
K, A [B, T, S, ST, C] D, LL3, LL2,
LL1 
Duplex 250 mm x 1 5/8 x ¼ in 
"Mechanical
Engineer." 

1958EOB 
Pic 
L, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at π. 
K, A [B, T, S, ST, C] D, DI 
HO
1773 

P253

1961EOB 
Pic 
LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1 Folded
at √10. 
K, A [B, TI_{2}, TI_{1},
SI] D, DI. TI divisions= 1/12 degree 
Duplex 250 x 41 x 5 mm 
Vectolog." Elaborate
clamshell case. Allplastic version of model
264. ¥2.400 in catalog 6911. 
HO 177400 (1964); Geotec 3413130 (1964+) 
P253 Special 
1967 
Pic 
LL3, LL2, DF [CF, CIF, CI,
C] D, L, LL1 Folded at √10. 
K, A [B, TI_{2}, TI_{1},
SI] D, DI 
Marked
"P253 Special" and "Vectolog." Only
difference from P253 is green CIF scale.


1965 
Pic 
LL3, LL2, DF [CF, CIF, CI, C] D, L, LL1 Folded
at √10. 
K, A [B, TI_{2}, TI_{1},
SI] D, DI,√3V.

Marked "P253 Special" and "Vectolog." Short additional scale on back marked "√3V" at left and and "volt" at right end.  
254W 
196368 
Pic 
LL/1, LL/2, LL/3, DF [CF, CIF, CI, C]
D, LL3, LL2, LL1 Folded at √10. 
K, A [B, TI, SI, C] D, DI, L  Duplex 250 mm x 1¾ x ¼ in. 
"High School Students". Basis for model 108 demo rule. Equal length stators.  
196372

Pic 
Traditional stators. 

254 WS 
1970s 
Pic 
Same as 254W but folded
at π. 
Same as 254W. 
Only
difference from 254W is where front scales
are folded. 
Only two specimens known.
Date codes "RC" (March 1967) and "UB" (Feb 1970) 

1969 
Pic 
Same as 254W.
Folded at √10. 
L, K, A [B, TI, SI, P] Q, Q', D,
DI 
With
P, Q, and Q' scales 
Date code "TC" = March 1969. 

1970s 
Pic 
K, A, [SIN COS, COS^{2},
TI, SI, C] D, DI,
L 
With stadia scales.  Equal stators date = "OC" (Mar 1964); others = "UB" (Feb 1970) or no code.  
1971 
Pic 
K, A [B, TI_{2},
TI_{1}, SI, C] D, DI,
L 
"High School Students." Traditional stators. Hemmi name on back of rule.  
1971 
Pic 
Same as 254W but folded at π. 
K, A [B, TI_{2}, TI_{1},
SI, C] D, DI, L 
Date
code "VC" = March 1971 

1970s 
Pic 
KI, K, AI,
A [B, S, T, CI,
C] D, LdB, P, DI 
May
set record for number of different inverse scales
on one side of a rule. 

1965 
Pic 
LL/1, LL/2, LL/3,
DF [CF, CIF, ST, CI, C] D, LL3, LL2, LL1 Folded at π. 
KI, K, AI, A [B, S, T, CI, C] D, LdB, P, DI  Equal
length stators. 

254WN 
1972EOB 
Pic 
LL/1, LL/2, LL/3,
DF [CF, CIF, CI, C] D, LL3,
LL2, LL1 Folded at √10. 
LL/0, K, A [B, TI_{2}, TI_{1}, SI, C] D, DI, L, LL0  "High School Students." Traditional stators. Hemmi name and model number on back of rule.  
254 WNS 
1972 
Pic 
Same as 254WN except
folded at π. 

1973 
Pic 
Same as 254WN. Folded
at √10. 
L, K, A, [B, TI_{2}, TI_{1},
SI, P] Q, Q', D, DI 

255 
195057 
Pic 
L, K, DF [CF, CIF, CI, C] D, χ, θ Folded at π. 
Sh_{1}, Sh_{2}, Th,
A [B, TI_{2}, TI_{1},
SI, C] D,LL3,LL2,LL1 
Duplex 250 mm x 1¾ x ¼ in 
"Expert Electrical Engineer." Replaced model 155.  
195861 
Pic 
L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at π. 
Sh_{1}, Sh_{2}, Th,
A [B, TI_{2}, TI_{1},
SI, C] D, χ, θ 

255D 
1961EOB 
Pic 
L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at π. 
Sh_{1}, Sh_{2}, Th,
A [B, TI_{2}, TI_{1}, SI, C] D, DI, χ, θ 

256 
195068 
Pic 
L/dB,
Neper, DF [CF, CIF, CI, C] D, LL3,
LL2, LL1 Folded at π. 
A, Ĺ [Ċ, SI, TI] D, l, F 
Duplex 250 mm x 1¾ x ¼ in 
Electrical Communications. Ĺ and Ċ scales are about half length.  
257 
195268  Pic 
L, A, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π. 
Ch AM, Ch NZ, M_{1} [M_{2},
^{o}F, ^{o}C,
^{o}K, F(t)] Kg/cm^{2}, mm Hg, in. Hg Vac.,
t_{ω} 
Duplex 250 mm x 1¾ x ¼ in 
"Chemical Engineer." 
Post 1491 (c195767); HO 1770 (1958) 
257L 
1971EOB 
Pic 
L, K, A, DF [CF, CIF,
CI, C] D,
LL3, LL2, LL1 Folded at π. 
Ch AM, Ch NZ, M_{1} [M_{2},
^{o}F, ^{o}C,
^{o}K, LM] mm Hg, Kg/cm^{2},
in. Hg Vac., t_{ω} 
"Chemical Engineer." Hemmi name on back of rule.  
258 
1951 
Pic 
LL0, LL/0, K, DF [CF, CIF, CI, C] D, R_{1}, R_{2},
L Folded at π. 
LL/1, LL/2, LL/3
[T T, SecT ST, Cos S, C] D, LL3, LL2,
LL1 
Duplex 250 mm x 1¾ x ¼ in 
VERSALOG Ia. About 30 specimens
marked "Hemmi 258" are known. All are also marked
"THE FREDERICK POST CO. NO 1460" or "THE HUGHES
OWENS CO. LIMITED NO. 1777." Click here for
a short history of model 258. 
Post 1460 Versalog (1951+); HO 1777 Versalog (1951+). For information about Versalog models Ib and II see the second page of this Catalogue Raisonne. 
259 
195058 
Pic 
L, K, DF [CF, CIF, CI, C] D, LL0, LL/0
Folded at π. 
LL/1, LL/2, LL/3,
A [B, T, S, ST, C] D, LL3, LL2, LL1 
Duplex 250 mm x 1¾ x ¼ in 
"Expert Mechanical Engineer." Replaces model 159.  
195863 
Pic 
LL/1, LL/2, LL/3,
DF [CF, CIF, CI, C] D, LL3,
LL2, LL1 Folded at π 
L, K, A [B, T, S, ST, C]
D, LL0, LL/0 
"Expert
Mechanical Engineer." Hemmi name moved to
back of rule. 

259D 
1953EOB 
Pic 
LL/1, LL/2, LL/3,
DF [CF, CIF, CI, C] D, LL3,
LL2, LL1 Folded at π 
L, K, A [B, T, S, ST, C]
D, DI, LL0, LL/0 

259DS 
1970s 
Pic 
LL/1, LL/2, LL/3,
DF [CF, CIF, CI, C] D, LL3,
LL2, LL1 Folded at π. 
LL0, LL/0, K, A [B, T, S, ST, C] D, √1,
√2, L 

260 
1964EOB 
Pic 
LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded
at π. 
LL/0, LL0, K, A [B, T, S,
ST, C] D, DI, P, L 
Duplex 250 mm x 1¾ x ¼ in 
"Advanced Engineer." {3 hairlines: A: C^{2}, hpC^{2}} Some rules c1970 have brand and model on bottom edge. Some marked UNIVERSITY on bottom edge. ¥4,800 in catalog 6911.  
260
Demo 
1964 
Pic 
LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL1 Folded at π.  LL/0,
LL0, K, A [B, T, S, ST, C] D, DI, P, L 
Duplex 1500 mm x _ 
Painted wood classroom demonstration
rule. Cursor is single wire. 

P261 
1965EOB 
Pic 
LL01, LL02, LL03,
DF [CF, CIF, CI, C] D, LL3,
LL2, LL1 Folded at π. 
T, ST, K, A [B, BI, CI, C] D, L, P, S  Duplex 250 x 46 x 5 mm 
"Advanced Engineer" (Darmstadt).
Stators white or pale blue. {4 hairlines on back
of cursor. A: C2, hpC2, D: C} 
TP 1420 (c1971 only) TP 44CB200 (1972+) Geotec 3413660 
P262  1965EOB 
Pic 
LL01, LL02, LL03,
DF [CF, CIF, CI, C] D, LL3,
LL2, LL1 Folded at π. 
K, A, R1, R2 [T2, T1, ST, S, C] D,
L, LL00, LL0 
Duplex 250 x 46 x 5 mm 
"Advanced Engineer" (Rietz). 
TP 1422 (c1971 only), TP 44CB220 (1972+) 
P263 
196469  Pic 
P_{1}, P_{2}, DF [CF, CIF, CI, C] D, LL, LL Folded at 360.  A, N [M, £, S/d, C] D, G 
Duplex 250 x 41 x 5 mm 
"Commerce." N, M have 365 divisions for dates. £,S/d = pound, shilling/pence. G is a set of conversion gauge marks  Geotec 3413155 (1967+) Hemmi 143 is pocket version. 
264 
1968EOB 
Pic 
LL3, LL2, DF
[CF, CIF, CI, C] D, L, LL1
Folded at √10 
K, A [B, TI_{2}, TI_{1},
SI] D, DI.

Duplex 250 mm x 15/8 x ¼ in 
Bamboo version of model
P253, Vectolog. 

264S 
1969 
Pic 
K, A [B, TI, SI, P] Q, D,
DI. 
P & Q scales,
Single TI scale. 

264M 
Pic 
K, A [B, TI_{2},
TI_{1}, SI] D, DI.

A mismarked model 264? Only known specimen was sold on Yahoo Japan, June 2018. Photo shows factory marking "264M."  
264S 
1970s 
Pic 
LL3, LL2, DF [CF, CIF, CI,
C] D, LdB, LL1 Folded at √10. 
K, A [B, TI_{2}, TI_{1},
SI] D, DI, χ, θ 

P265 
196872 
Pic 
P_{1}, P_{2},
DF [CF, CIF, CI, C] D,
LL2, LL1 Folded at 360 
A, D [G, 024,
N] M, 024 
Duplex 250 x 46 x 4 mm 
"Business."
N, M have 365 divisions for dates. G is
a set of conversion gauge marks. Instructions &
scale labels in Japanese. 

266 
1961EOB 
Pic 
(LL/3 and LL/1),
LL/2, LL2, A [B,
BI, CI,
C] D, dBL, S, T 
X_{L}, X_{C}, F, (τ_{1}
and P), [(τ_{2} and Q), L, C, C_{z}] L, Z, f_{o} 
Duplex 250 mm x 1¾ x ¼ in 
"Electronics." Announced in 1961 but not in Hemmi catalogs until 1966. Early specimens (1962) marked "Developed by SONY." LL/3, LL/1, τ_{1}, τ_{2}, P, Q are partial length scales. Also sold as Geotec 3413550 (1966+)  
P267 
1971EOB 
Pic 
³√3, ³√2, ³√1, DF [CF, CIF, CI,
C] D, √1, √2, δ(unif.) Folded at √10 
4√4, 4√3, 4√2, 4√1 [λ_{δ}(conc), λ_{δ}(Trape), λ_{M}, P] Q, L, T, S 
Duplex 250 x 46 x 5 mm 
"Structural Design." 

269 
1965EOB 
Pic 
L, F, K, A [B, K', CI, C] D, LL3, LL2, LL1 
CL, SL, M, TL [R, ST, T, S, C] D,
DI, SinCos1, SinCos2 
Duplex 250 mm x 1¾ x ¼ in 
"Civil Engineer." 

P270 
1971EOB 
Pic 
J, J
[T(ºK), Q(m³/s), Q(m³/s)] Hm(m), Q(m³/s),
Ht(m) 
X, X, Cz,
Cmax(PPM)
[He(m), Cy,
CI, C] D, A, L 
Duplex 250 x 46 x 5 mm 
"Pollution A." (air quality analysis) 19 scales in black, red and blue.  
P271 
1974 
Pic 
x,x_{s}(g/kgDA),
(ice), T_{φ},t_{φ}(ºC)
[h_{w},h_{s}(mmhg),
CI,
C] D, v, v_{a}(m^{3}/kgDA), t(ºC), t(ºF) 
[t(ºC)(ice),
t'_{2.5}, t(ºC)] 
Open 250 x 46 x 5 mm 
Moist air. There are 13 scalesmost
with complicated labels. 

274 
1973EOB  Pic 
L, DF [CF,
CIF, CI, C] D,
LL3, LL2, LL1 Folded at √10 
K, A [B, TI_{2}, TI_{1},
SI, C] D, DI 
Duplex 250 mm x 1¾ x ¼ in 
Late model general engineering rule with scales folded at √10 and trig scales inverted. Likely sold only in Japan.  
274S 
Pic 
K, A [B, TI_{2},
TI_{1}, SI, C] D, DI,
dB 

NA 
dB, K, A [B, TI_{2},
TI_{1}, SI, C] D, DI,
χ, ϴ 

275 
195058 
Pic 
L, K, DF [CF, CIF, CI, C] D, χ, θ Folded at π. 
Sh_{1}, Sh_{2}, Th, A [B,
TI_{2}, TI_{1}, SI,
C] D, LL3, LL2, LL1 
Duplex 500 mm x 1¾ x ¼ in 
20inch Version of Model 255.  
195863 
Pic 
L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at π. 
Sh_{1}, Sh_{2}, Th, A [B,
TI_{2}, TI_{1}, SI,
C] D, χ, θ 
20inch Version
of Model 255. Some with green scale labels on cursor. 

275D 
196369 
Pic 
L, K, DF [CF, CIF, CI, C] D, LL3, LL2, LL1
Folded at π. 
Sh_{1}, Sh_{2}, Th, A [B,
TI_{2}, TI_{1}, SI,
C] D, DI, χ, θ 
20inch Version
of Model 255D. Some with green scale labels on
cursor. 

279 
195058 
Pic  L, K, DF [CF, CIF, CI, C] D, LL0, LL/0 Folded at π. 
LL/1, LL/2, LL/3,
A [B, T, S, ST, C] D, LL3, LL2, LL1 
Duplex 500 mm x 1¾ x ¼ in 
20inch Version of Model 259. Some with green scale labels on cursor.  
195863 
Pic 
LL/1, LL/2, LL/3, DF [CF,
CIF, CI, C] D, LL3, LL2,
LL1 Folded at π. 
L, K, A [B, T, S, ST, C] D, LL0, LL/0 

279D 
196369 
Pic 
LL/1, LL/2, LL/3, DF [CF, CIF, CI, C] D, LL3, LL2, LL
Folded at π. 
L, K, A [B, T, S, ST, C] D, DI, LL0, LL/0 
20inch Version
of Model 259D. Some with green scale labels on
cursor. 

P280 
195972 
Pic 
T, K, A [B, CI, C] D, L, S, ST 
[LL1, LL2, LL3] 
Open 250 x 46 x 4 mm 
"Beginners." 
TP 1414 (c1971 only), 44BB140
(1972+); Geo 3413645; Ahrend P280. 
280S 
1976? 
Pic 
L, K, A [B,
CI, C] D, S, ST, T 
cm [LL1, LL2, LL3] inches 
Open 250 mm 
All plastic. Marked "HEMMI,
JAPAN, 280S" but probably made by D&P. Only
known specimen found in Thailand 
Ahrend P281; Same as Aristo 0903 except back of Aristo slide is blank. 
P281 
197072 
Pic 
T, K, A [B,
CI, C] D, L, S, ST 
Blank 
Open 250 x 46 x 4 mm 
Rietz.  TP 1410 (c1971
only), 44BB100 (1972+); Geo 3413640 
P283 
197071 
Pic 
K, A, DF [CF CI, C] D, L, T, S Folded at π. 
[LL1, LL2, LL3] 
Open 250 x 46 x 4 mm 
Beginners. 
Ahrend P283. 
Models 300999: Specialty
Slide Rules 

300 
WWII  Pic 
G, E [F, CI, C] D, M 
[Blank] 
//Closed 250 x 34 x 8.5 mm 
Decimal Calendar
Rule. G scale is folded at 365; E & F folded
at 3.042 = 365/12. M scale is set of gauge marks for Japanese
weights & measures. Japanese language. 

301 301A 
195469 
Pic 
τ, ω [CI,
f, P, C] D, A, db 
[θ, θd, g',
g] 
//Closed 250 x 34 x 11 mm 
Control Engineering. Four
cursors! 301A is 301 plus a transparent overlay. 
Post 1490 (1957ca67) 
305 
195970 
Pic 
TmV/S, ℓ_{1} [ℓ_{2},
m, a] T, v 
[N, F, u] 
//Closed 125x26 x _ mm 
Acoustic Design. Patents 225936, 225937.  
400 
195968 
Pic 
Y, A [B, CI, C] D, LL3, LL2, LL1 
E_{ß}, R(AI), Dist, Dose Rate [S, Isotopes (4 scales)]
E_{v}, Pb,
Fe, Al 
Duplex 250 mm x 1¾ x ¼ in 
Radioisotope Engineering. 

401 
196669 
Pic 
d, W [Nt, D, MI, M] L 
τo,
P [d, D, D, Na(δ)]
k(P), d 
Duplex 250 mm x 15/8 x ¼ in 
"Coiled Spring Rule." 

P402 
196669 
Pic 
15 scales in black, red, blue and green  all labeled in Japanese. Only three scales are full length. Scale arrangement and range of variables differs slightly between the two models.  A, DF [CF, CIF, CI, C] LL (2 scales) Folded at √10. 
Duplex 250 x 41 x 5 mm 
"Tanabe Corporate Performance Analysis." P402 for manufacturing businesses; P403 for wholesale and retail distributors. Rule and instructions in Japanese.  Click here for an illustrated explanation of models P402 and P403 by Atsushi Tomozawa. 
P403 
196669 
Pic 

405 
195068 
Pic 
C_{2}F, Al_{2}O_{3}
[Fe_{2}O_{3}, C_{2}AF]
C_{2}A, SO_{3}, CaSO_{4} 
C_{2}S (A Scale), CaO [SiO_{2}(for
C_{3}S), Fe_{2}O_{3},
SiO_{2}(for C_{2}S), SO_{3}/Al_{2}O_{3}]
C_{3}S, C_{2}S (B Scale) 
Duplex 250 mm x 1¾ x ¼ in 
"Cement Composition."
Scale labels are chemical symbols, numbers
subscripted. No scales are logarithmic. Fe2O3
and SiO2(for C2S) are separate short scales on same
line. Accompanying Instruction Manual published by Portland
Cement Assoc. Skokie, Ill, May 1959. 

410 
195969 
Pic 
G_{2},
G_{1}, F_{2},
F_{1} [x, F_{1}G_{1}]
Z_{1}+Z_{2}, G', F' 
G_{2},
G_{1}, F_{2},
F_{1} [x, CI, C] D, A 
Duplex 250 mm x 1¾ x ¼ in 
"Involute of Gear Wheel." 

451 
1969 
Pic 
Eight specialized scales.
Center scales are not full length. 
LL/3, LL/2, LL2,
A [B, BI, CI, C] D, dBL, S, T 
Duplex 250 mm 
"Field Intensity."
There are bamboo and allplastic versions of this rule; both are marked "451." (Not "P451") 

P452 
196872 (For Post) 
Pic 
LL1, LL2, LL3, CR_DF [T_CF,
CIF, %_CI, T_C] R_D, L, in, cm Folded at π 
ST, 3n2_K, 2n1_A [B, BI, CI, C]
D, P, S, T 
Duplex 250 x 46 x 4 mm 
"Business." Some marked
"System H. Kroon." Yellow slide, green brackets.
(Post & TP have blue slide & brackets) 
TP 1426 (c1971 only), 44CB260
(1972+) 
500 
1943 
NA 
125 mm x _ 
"For Airplane." ¥8.50 in 1943
price list. No other mention. 

640S 
1972 
Pic 
K, DF [CF, CIF, CI,
C] D, A, L Folded at √10. 
[STI, TI_{2}, TI_{1},
SI, CI] 
//Closed 250 x 45 x 9 mm 
Desk Rule. Bamboo between
thick plastic 

641 
1975 
Pic 
K, A, DF [CF, CIF, B, CI,
C] D, DI, L Folded
at √10 
[STI, TI_{2}, TI_{1},
SI, CI] 
//Closed 250 x 45 x 9 mm 
Desk Rule. Bamboo between
thick plastic. 

642T 
1973 
Pic 
K, A [B, BI, CI, C] D, DI, L with overrange 
[T_{2}, T_{1}, ST,
S] 
//Closed 250 x 45 x 9 mm 
Desk version of 64T. Bamboo
between thick plastic. {3 hairlines: D: C, C}. 
Ahrend 643T 
651 
1969 
Pic 
K, A, DF [CF, CIF, B, CI, C]
D, DI, L Folded at √10. 
[TI_{2}, TI_{1},
STI, SI, C] 
//Closed 250 mm x 1½ x 7/16 in 

Models
1xxx: Circular Slide Rules


1001 
1971 
Pic 
A, D, C, CI, L 
Blank 
Circular 80 mm 
Circular. 
Geotec 3413910 
1002 
1971 
Pic 
A, D [C, CI] 
Blank 
Circular 80 mm 
Circular. Less elaborate
than 1001. 

2600 Series Rules Introduced in 1940 (February 11, 1940 was the 2600th Aniversary of the Founding of Japan)  
2600 
194051 
Pic 
DF [CF, CI,
C] D, L Folded at √10. 
K, A [B, TI_{2}, TI_{1},
SI_{1}] D, DI 
Duplex 250 mm x 15/8 x ¼ in 
General Engineering and Business.


2634 
1949EOB 
Pic 
K, DF [CF, CI,
C] D, A Folded at √10. 
[TI_{2}, TI_{1}, L, SI]

//Closed 125 x 26 x 5 mm 
Pocket 2664. 

P2634 

Pic 
K, DF [CF, CI, C] D, A Folded at √10. 
[TI_{2}, TI_{1}, L, SI]  Closed 125 mm x _ 

2640 
194968 
Pic 
ℓ, A [B, CI, C] D 
[S, K, T] (S keyed to C/D) 
Closed 200 x 28 x 8 mm 
Beginners Slide Rule
for 50W. Plastic cursor. 

2641 
Pic 
DF [CF, CI, C] D, A Folded at √10. 
Blank 
Closed 200 x 28 x 8 mm 
Beginners Slide Rule for 45
(which, itself, was a beginner's rule). Plastic
cursor. 

2645 
WWII 
Pic 
DF [CF, CI, C] D, A Folded at √10. 
[TI, L, SI] 
Closed 200 x 28 x 8 mm 
Essentially identical to model
45 except CI scale is black. 
Only one specimen known. 
2662 
196669?  Pic 
K, A, DF [CF, CIF, CI, C]
D, DI, L Folded at √10. 
[B, TI, SI, C]  //Closed 250 x 34 x 11 mm 
Some with 13013 cm scale on bottom edge.  See Hemmi Catalogue Raisonne 2 for
a slide projector version of this rule. 
2664  WWII 
Pic 
K, DF [CF, CI,
C] D, A+L Folded at √10. 
[TI_{1}, TI_{2}, SI_{2}, SI_{1}]  Closed 250 x 34 x 9 mm 
Wartime construction
(bare vertical edges and back) No model number
on rule. A+L scale is left half of A scale joined to right
half of L scale. 

MIOJ 
Pic 
K, DF [CF, CI, C] D, A Folded
at √10. 
[TI_{2}, TI_{1},
L, SI_{1}] 
//Closed 250 x 34 x 11 mm 
Better quality construction. Full length A scale; L scale replaces SI_{2.}  
194958 
Pic 
K, DF [CF, CI,
C] D, A+L Folded at √10. 
[TI_{1}, TI_{2}, SI_{2},
SI_{1}] 
A+L scale is left half of A scale joined to right half
of L scale. 

2664S 
195869 
Pic 
K, DF [CF, CIF, CI, C] D, A
Folded at √10. 
[TI_{2}, TI_{1}, L, SI]

//Closed 250 x 34 x 11 mm 
Same as 2664 except 10 mm longer
overall and green CIF scale added. 
¥2,200 in catalog dated 6911 
2664SS 
1967 
Pic 
K, A, DF [CF, CIF, CI, C] D,
DI Folded at √10 
[TI_{2}, TI_{1}, L, SI]

//Closed 250 x 34 x 11 mm 
Same as 2664S except DI scale
added. 

2670 
MIOJ 
Pic 
K, A [B, CI,
C] D, L 
[S, S&T, T] 
//Closed 500 x 40 x 12 mm 
Long Rietz. Shortlived replacement
for model 70. {3 hairlines: D: C, C}. 

2690 
195168

Pic 
L, D [M1, M2, C] D, A 
[S, S&T, T] 
//Closed 250 x 34 x 11 mm 
Stadia. {3 hairlines: D: C,
C}. 

2690A 
195455 
NA 
Same as 2690  "2690A" marked on case to distinguish
model 2690 from proposed centesimal degree model 2690B.
Rules are marked just "2690." 

Odds and Ends 

P3526 
1970s? 
Pic 
S, K, A [B, CI, C] D, L, T 
None 
Closed 250 x 40 x 3 mm 
Beginner's allplastic
slide rule marked "HEMMI, Japan, NO P3526"
but manufactured by Hope Slide Rule Mfg Co, Tokyo. Same
as Hope model 51. (The only known 'Hemmi' example was found
in New Zealand.) 
