Skip to product information
1 of 2

Lot 152 - Antique Celluloid Advertising Tap Drill Size and Drill Speed Calculator, the Cleveland Twist Drill Co., Cleveland, Ohio, U.S.A., Copyright 1911, 3-1/8" W

Lot 152 - Antique Celluloid Advertising Tap Drill Size and Drill Speed Calculator, the Cleveland Twist Drill Co., Cleveland, Ohio, U.S.A., Copyright 1911, 3-1/8" W

Opening Bid $5 No Bids
Bidding opens soon
Antique celluloid rotary calculator produced by The Cleveland Twist Drill Co., Cleveland, Ohio, U.S.A., with offices in New York and Chicago, copyright 1911. The front side provides tap drill sizes with columns for tap size, U.S. standard thread count, and corresponding drill number, along with decimal equivalents around the outer ring. The reverse side provides drill speeds for wrought iron, machinery steel, and soft tool steel, with revolutions per minute for both high-speed and carbon steel drills indicated through a rotating window. Originally priced at 25 cents.

The rotating inner disc is present but the rivet is loose at the center hole. There is staining and discoloration to both sides, with a small area of material loss along one edge on the front and scattered foxing on the reverse.
Dimensions: 3-1/8" W

Auction Date: 10/08/2026

View full details