The Load Lifting Approved Code of Practice states:
4.4 Wire rope (bulldog) clips
4.4.1 Do not use wire rope (bulldog) grips on any load-hoisting rope. They are only suitable for forming an eye on stays or guys.
4.4.2 Wire rope (bulldog) grips must comply with DIN 1142 or equivalent Standard as per the drawing.
The performance of wire rope grips is very dependant on the nuts being torqued to the correct figure as well as fitting the correct number of grips the right way on the rope .
Depending on the standard that the grips are made to the torque is different even for the same size rope . Also some standards give a figure with the threads greased and other with the threads dry and it is very important the right method is used .
For example :
Federal Spec 450 grips for 19mm rope has a tightening torque of 18kg force per metre on dry threads . This means you need to pull 36kgs on the end of a 500mm long spanner .
DIN 1142 grips for 19mm rope has a tightening torque of 7kg force per metre on lubricated threads . This means you need to pull 14kgs on the end of a 500mm long spanner .