Archived Tool Detail
Vintage Keuffel & Esser Slide Rule N4081-3 Log Log Duplex Decitrig with Original Case
Vintage Keuffel & Esser N4081-3 Log Log Duplex Decitrig slide rule in exceptionally clean original condition with its fitted K&E carrying case. Made in the USA and showing remarkably little apparent use, with crisp scales, an intact glass cursor, smooth-moving slide, and only mild age-related yellowing.
Detailed Description
A beautiful example of a classic American engineering and calculating instrument: the Keuffel & Esser N4081-3 Log Log Duplex Decitrig slide rule.
This full-size duplex rule was manufactured by Keuffel & Esser Co. in the United States. The edge is clearly marked N4081-3 LOG LOG DUPLEX DECITRIG, along with the K&E name, Made in U.S.A., patent numbers, and a 1947 copyright marking.
The 1947 marking is the copyright date for the design and scales rather than a confirmed manufacturing date for this individual rule. This version of the 4081-3 is associated with the later 1950s/early 1960s production period.
Tool Details
- Maker: Keuffel & Esser Co. (K&E)
- Model: N4081-3
- Type: Log Log Duplex Decitrig slide rule
- Made in U.S.A.
- Full-size approximately 12½-inch rule
- Duplex scale arrangement
- Glass cursor with metal frame
- K&E logo and red/black scale markings
- Original fitted black carrying case
- Leather retaining/carry strap
- Copyright 1947 marking
- Multiple U.S. patent numbers marked along edge
Condition
This is an exceptionally clean vintage example and appears to have seen very little use.
The scales and numbers remain crisp, sharp and highly legible on both sides. The rule shows mild, even yellowing consistent with age along with a few tiny marks and spots visible on close inspection. The wood laminations and edges present very well.
The center slide moves smoothly and evenly. The cursor is intact and slides properly. Metal end fittings and cursor frame remain bright with minor age and handling marks.
The original fitted K&E case is also in very good vintage condition. It shows normal age and handling wear, particularly around the opening and leather strap, but remains attractive and functional.
Please examine all photographs closely. The close-up photographs intentionally show the surfaces, markings and age-related imperfections at high magnification.
Preservation
Because of its unusually clean original condition, this rule was deliberately not aggressively restored.
It received only a gentle surface wipe to remove loose dust and grime. No abrasives, refinishing, whitening treatment, metal polish, oils or waxes were applied to the slide rule. The original finish, markings and natural age coloration have been preserved.
Ideal For
An excellent piece for a slide-rule collector, engineer, mathematician, scientist, vintage drafting-tool collection, technical office display, or as a distinctive gift for someone interested in the history of engineering and pre-electronic calculation.
This is also a functional instrument: the center slide and cursor both operate smoothly.
A printed care sheet is included with the purchase to help preserve the slide rule and case.
Highlights
- Vintage Keuffel & Esser engineering slide rule
- N4081-3 Log Log Duplex Decitrig model
- Made in U.S.A.
- Exceptionally clean original condition
- Crisp red and black scale markings
- Smooth-moving center slide
- Intact glass cursor
- Original fitted K&E carrying case
- Attractive mild age coloration
- Minimal preservation cleaning only
- Excellent engineering or mathematics collectible
- Printed care sheet included