BS 3409-2:1966

This standard BS 3409-2:1966 Specification for the tapping of holes to receive wire thread inserts (UNC and UNF threads) is classified in these ICS categories:

• 25.100.50 Taps and threading dies

This British Standard comprises three sections:

Section 1, which specifies limits of size for tapped holes to accommodate wire thread inserts to provide thread sizes from No. 2 to No. 12 UNC and UNF;

Section 2, which recommends screwing taps intended to produce holes to the limits of size specified in Section 1;

Section 3, which gives a recommended gauging system for checking the tapped holes.

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.