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A-A-625A

December 7, 1987

SUPERSEDING

A-A-625

March 27, 1980

COMMERCIAL ITEM DESCRIPTION

TAP, THREAD CUTTING

(REGULAR, FRACTIONAL INCH SIZES)

The General Services Administration has authorized the use of this

Commercial Item Description in preference to Type I of Federal

Specification GGG-T-70.

This commercial item description covers general purpose, ground thread, high-speed steel taps with straight flutes for use in hand and machine tapping operations.

Salient characteristics:

Design. Taps shall be of the regular hand type with straight flutes, and be in accordance with the latest revision of American National Standard ANSI B94.9, except as otherwise indicated by an asterisk in the table below.

Material. Material shall be high-speed steel of the same grade used for taps supplied to the commercial market for general purpose applications.

Hardness. Taps shall be hardened and tempered so as to indicate a Rockwell C62-66 hardness in at least eighty percent of the threaded section from the threaded end. The shank and square drive end may have other suitable heat treatment characteristics to prevent twisting and breaking of the tap.

Finish. Threads shall have a ground finish. Other areas shall be finished in accordance with commercial practice. Coatings or surface treatments, if provided, shall be suitable for general purpose tapping applications.

Thread size, type of chamber, pitch diameter and number of flutes. Shall be as shown in the following table for the National Stock Number (NSN) specified. Except as indicated, threads shall be right hand direction.