IML PERFORMS REGULAR CHECKING OF THE THREAD IN ACCORDANCE WITH ITS PROCEDURE AND WITH ANSI/ASME B1.20.1 NORMATIVE
The chamfering illustrated is at 45 deg. angle and is approximately 1/2 pitch in depth. However, these details are not requirements and are given only for information on the illustration shown. The chamfered portion of thread and the full chamfering cone are indicated by dotted lines.
The reference point for the internal product thread is the starting end of the fitting, providing the chamfering does not exceed the major diameter of the internal thread. When a chamfering on the product thread exceeds this limit, the reference point becomes the last thread scratch on the chamfering cone, as illustrated. Allowance must be made for depth of counterbore on counterbored fittings.