ISO 898-7 1st Edition, January 1, 1992
Mechanical Properties of Fasteners - Part 7: Torsional Test and Minimum Torques for Bolts and Screws with Nominal Diameters 1 mm to 10 mm
Published By:International Organization for Standardization (ISO)
This part of ISO 898 specifies a torsional test for the determination of the breaking torque of bolts and screws with nominal diameters 1 mm to 10 mm with property classes 8.8 to 12.9 in accordance with ISO 898-1. The test applies to bolts and screws with thread less than M3 for which no breaking and proof loads are indicated In ISO 898-1, as well as to short bolts and screws with nominal diameters 3 mm to 10 mm which cannot be subjected to a tensile test.
The minimum breaking torques are not valid for hexagon socket set screws.