ASME - ANSI B94.28
Die Buttons Basic Straight Relief, Press Fit
|Publication Date:||1 January 1970|
This Standard covers the American National Standard practice for basic-straight relief press fit die buttons including dimensions, tolerances, nomenclature, sizes and shapes. The Standard covers round, oblong, square and rectangular hole die buttons for up to one inch diameter maximum pierced hole size, both headless and head type.
Headless die buttons are intended primarily for retention in the die block or retainer entirely by press fit, and for installations in thick die blocks in counterbored holes. Head type die buttons are intended for retention in the die block or retainer by press fit and/or by the shoulder action of the head, and for applications requiring increased bearing area for the die button.
In the interest of simplicity, the past practice of having increasingly larger press fit allowances on headless die buttons as nominal body size increased has been changed to merely stating a tolerance on the body or "D" diameter. This tolerance has been made the same as on head type die buttons and head type punches (Ref. USAS B94.14-1968). It is felt that the standard can control tolerances of components but cannot necessarily dictate or control the fit of the die button in the holder or retainer plate because it is made by others for various specific applications and does and should vary with conditions.