Recess Inspection Gages:
- ANSI/ASME Type 1: Phillips #0, #1, #2, #3, #4
- ANSI/ASME Type IA: POZI-DRIVE #0, #1, #2, #3, #4
- (registered trademark of the Phillips Screw Co.)
- ANSI/ASME Type III: Square socket #1, #2, #3, #4
- Hex Socket (GO element) .050″ through 9/16″; 1.5mm
- through 14mm
- 6-Lobe Recess (GO element) T-6 through T-55
Recess Penetration Depth – this is the distance a precisely made gaging element enters a fastener’s recess. This is usually less than the “recess depth”. This measurement is an indication of how deeply a driving bit will engage in the recess.
Recess Depth – the deepest point in a fastener’s recess. This is usually a sharp point in the center of the recess.
Recess Torsional Strength – this is the ability of a recess to resist damage from driver bit camout or reaming when a rotational force (torque) is applied to the bit engaged in the recess with a specific amount of end load pressure applied to keep the driver engaged in the recess. This requirement is defined in MIL-S-87114A.