①,The mechanical properties of the screw as a component of a combination tapping screw must comply with those of ISO 2702. After assembly and heat treatment, the disc must have a hardness of 90 HV to 320 HV. The Vickers hardness test must be performed according to ISO 6507-1. Test load: HV 10 for a nominal thickness h ~ 1, 2 mm Test load: HV 30 for a nominal thickness h> 1, 2 mm Before assembling appropriate precautions must be taken ②,Designation for screws ISO 7049, Pan head tapping screws with Phillips, S2 ③,Abbreviation for washers: ISO 10669, Flat washers for combination tapping screws, Normal N, Great L |