Collection of pages from K&E catalogs for the 4081-3 Family of Slide Rules
4080-3 & 4081-3 Family Groups
Description:
The 4081-3 family of slide rules are duplex type of slide rules. The 4080-3 and 4081-3 were constructed on a mahogany frame with celluloid laminated to the surface except for a few all plastic versions. The markings are engine divided on the mahogany framed rules. These rules are identical except for the scale graduations of the trig scales. The 4080-3 is divided in degrees and minutes where as the 4081-3 is divided in degrees and decimal degrees on its trig scales. Of the catalogs available the first release was shown in the 1937 catalog and price list.
This is the second series of slide rules called "Log Log Duplex Trig" (4080-3) and "Log Log Duplex Decitrig" (4081-3). This group was evolved from the 4091-3 family in 1937 and the earlier 4092-3 family of slide rules. The 4081-3 family of slide rules became the main stay for the K&E line of slide rules in the 1940s, 50s, and 60s,
The construction of the 4081-3 family evolved during the life of the family group. From 1937 through 1947 the laminate covered the entire surface of the rules except for the ends and all printing was on the front and rear surfaces. From 1947 through 1952 the model numbers and other logo type information was engraved on the top edge of the rule. From 1952 through 1972 the top and bottom surfaces of the rules showed some wood with laminate inlayed in it. Examples of inlaid laminate on the edges can be found in the last three scale sets. The model numbers were engraved on the laminate inlay. Also several different plastic versions of the basic 4081-3 family were produced.
The 4081 family has at least five distinctly different scale sets in its lifetime without a change in the model numbers. In 1962 the model numbers were converted to 68 xxxx series of numbers. The last scale set change happened in 1956.
1937 (4080-3 & 4081-3) Scale sets:
- Front: L LL1 DF = CF CIF CI C = D LL3 LL2
- Rear: LL00 LL0 A = B T ST S = D DI K
1939 (4080-3, 4080-5, 4081-3, & 4081-5) Scale sets:
- Front: L LL1 DF = CF CIF CI C = D LL3 LL2
- Rear: LL0 LL00 A = B T ST S = D DI K
1948 (N4080-3, N4080-5, N4081-3, N4081-5, & N9081-3) Scale sets:
- Front: LL02 LL03 DF = CF CIF CI C = D LL3 LL2
- Rear: LL01 K A = B T ST S = D L LL1
1953 (4181-1) Scale sets:
- Front: LL02 LL03 DF = CF CIF CI C = D LL3 LL2
- Rear: LL01 L K A = B T ST S = D DI LL1
1954 (4080-3, 4080-5, 4081-3, 4081-5, 4181-3, 68 1308, 68 1313, 68 1318, & 68 1323) Scale sets:
- Front: LL02 LL03 DF = CF CIF CI C = D LL3 LL2
- Rear: LL01 L K A = B T ST S = D DI LL1
1955b (4081-3, 4081-5, 4181-1, 4181-1C, E4181J, 4181-3, 68 1200, 68 1205, 68 1210, 68 1215, 68 1220, 68 1251, 68 1256, 68 1261, 68 1282, & 68 1287) Scale sets:
- Front: LL02 LL03 DF = CF CIF CI C = D LL3 LL2
- Rear: LL01 L K A = B T SRT S = D DI LL1
The following models are part of the 4081-3 family and vary in length and material types:
- 4080-3 ---- 10" Log Log Duplex Trig
- N4080-3 -- 10" Log Log Duplex Trig
- 4080-5 ---- 20" Log Log Duplex Trig
- N4080-5 -- 20" Log Log Duplex Trig
- 4081-3 ---- 10" Log Log Duplex Decitrig
- N4081-3 -- 10" Log Log Duplex Decitrig
- 4081-5 ---- 20" Log Log Duplex Decitrig
- N4081-5 -- 20" Log Log Duplex Decitrig
- 4181-1 ---- 5" Log Log Duplex Decitrig Plastic
- 4181-1C -- 5" Log Log Duplex Decitrig Plastic, Green Leather Sheath without pocket clip
- E4181J --- 5" Log Log Duplex Decitrig Plastic, Tan Leather Sheath with pocket clip
- 4181-3 ---- 10" Log Log Duplex Decitrig Plastic
- N9081-1 -- 5" Log Log Duplex Decitrig Plastic
- N9081-3 -- 10" Log Log Duplex Decitrig Plastic
- 68 1200 (4081-5) --- 20" Log Log Duplex Decitrig with Sewed Leather Case
- 68 1205 (4081-5) --- 20" Log Log Duplex Decitrig with Synthetic Leather Case
- 68 1210 (4081-3) --- 10" Log Log Duplex Decitrig with Sewed Leather Case and belt clip
- 68 1215 (4081-3) --- 10" Log Log Duplex Decitrig with Sewed Leather Case
- 68 1220 (4081-3) --- 10" Log Log Duplex Decitrig with Synthetic Leather Case
- 68 1251 (4181-3) --- 10" Jet-Log Plastic Slide Rule with Sewed Leather Case
- 68 1256 (4181-3) --- 10" Jet-Log Plastic Slide Rule with Synthetic Leather Case
- 68 1261 (4181-1) --- 5" Jet-Log Jr. Plastic Slide Rule with leather sheath and pocket clip
- 68 1282 (4181-1) --- 5" Log Log Duplex Decitrig Plastic with leather sheath and pocket clip
- 68 1287 (4181-1) --- 5" Log Log Duplex Decitrig Plastic with leather sheath
- 68 1308 (4080-5) --- 20" Log Log Duplex Trig with Sewed Leather Case
- 68 1313 (4080-5) --- 20" Log Log Duplex Trig with Synthetic Leather Case
- 68 1318 (4080-3) --- 10" Log Log Duplex Trig with Sewed Leather Case
- 68 1323 (4080-3) --- 10" Log Log Duplex Trig with Synthetic Leather Case
History:
The 4080-3 and 4081-3 were first shown in the 1937 catalog. They last appeared in the 1972 catalog.
- 1936 - The first known sale of a 4080-3 was at the Naval Academy in the fall of 1936. This rule has a circular K&E logo.
- 1937 - The 4080-3 and 4081-3 were first shown in catalogs.
- 1939 - The scale set was changed. The 4080-5 and 4081-5 were released.
- 1948 - The scale set was changed. Model numbers are engraved on top. The model numbers had the 'N' prefix added to the model numbers. This change was first shown in the 1948 price list for the 1944 catalog. The 1947 price list dated July 1, 1947 does not show the 'N' models. Sometime in 1952-1953 the inlaid laminate edges were introduced. The Doric N9081-3 was first shown. The N9081-3 was the first all plastic frame slide rule in 4081 family.
- 1949 - The N9081-1 was first shown.
- 1952 - The N9081-1 and N9081-3 are not shown. The N4181-3 is first described.
- 1953 - The 4181-1 is first described. It has the scale set of the 4080/4081 family with the DI scale first shown in 1954
- 1954 - The scale set was changed. Top and bottom have inlays and the model numbers are engraved on the top. The 'N' prefix was droped from the model numbers.
- 1955b - The scale set was changed. ST scale was changed to SRT on the 4081s only.
- 1959 - The 4181-1C was mentioned in the 1959 Price List.
- 1960 - The E4181J was mentioned in the 1960 Short Form Catalog.
- 1962 - The model numbers were converted to 68 xxxx series numbers. The Jet-Log and Jet-Log Jr. were introduced. 14 different models were shown in this catalog.
- 1967 - The 20" versions of the 4080-5 were not shown in this catalog.
- 1972 - Only 4 models of the 4081-3 family are shown in this catalog. The 4080-3 version was not shown.
Links to catalog pages for the 4080-3 and 4081-3 family of slide rules:
The 4181-1 5" Plastic slide rule follows a different path in the catalogs. The following are links to catalog pages for the 4181-1 slide rules:
Link to scans of 4080-3 and 4081-3 slide rules.