BSI - BS 3409-2
Specification for The tapping of holes to receive wire thread inserts (UNC and UNF threads) - Part 2: Diameters below 1/4 in
|Publication Date:||31 January 1966|
|ICS Code (Taps and threading dies):||25.100.50|
Limits of size for tapped holes to accommodate wire thread inserts to provide thread sizes from No. 2 to No. 12 UNC inclusive and from No. 2 to No. 12 UNF inclusive. Recommendations for general dimensions and limits of size on the threaded portion of screwing taps intended to produce holes to the limits specified; details of a recommended gauging system for checking them.