Collection of pages from K&E catalogs for the 4071-3 Family of Slide Rules


The 4070-3 and 4071-3 family of slide rules are duplex type slide rules. The 4070-3 and 4071-3 are identical except that their Trig scales have different graduations. The Trig scales on the 4070-3 are divided in degrees and minutes where as the 4071-3 is divided in decimal degrees. These slide rules were only offered in 10" versions. A 5" plastic slide rule, the 4168-1, was offered in the mid 1950s that was very similar with a sub-set of the scales but it will not be included in this discussion.

For a short period on time in the early 1950s when the Doric series was released. The 9071-3 was made on a plastic frame. To this date there is no documentation that it existed, however there is an example in this collection. The 9071-3 is identical to the 4071-3 of that time except for the plastic frame.

These slide rules were constructed on a mahogany frame with celluloid laminated to the surface. The markings are engine divided. The scales on the 4070-3 and 4071-3 are as follows:

These slide rules were an evolution of the 4088 family of slide rules. They are constructed on the same frame and the scales are similar. For a comparison, the scales of the 4088s are shown:

The following models are part of the 4071-3 family:


The 4070-3 and 4071-3 first appeared in the 1939 catalog. The 4071-3 family last appeared in the 1967 catalog. The following is a brief history of the 4071-3 family of slide rules as is told in the K&E catalogs that are available at this time. Exact timing is not possible because of the time between catalogs.

Links to catalog pages for the 4071-3 family of slide rules:

Link to scans of 4071-3 Family of Slide Rules