Nickel chrome plating cracks during torque test of screw driver

A. Pre-treatment of your base metal is the clue. Spring steel (high carbon) requires etching and a thorough de-smut step before plating to obtain maximum adhesion. A final low temp bake may also help.

A. Hello Hemant. Actually, I don't think your premise is correct. Vanadium is very important towards making steel alloys tough and strong, and is widely used in shafting and internal engine and motor parts, springs, firearms, etc. Rather, I think I would say that chrome vanadium steel is ideally suited to hand tools, and that's why you hear about it in that application.

It delivers the metallurgical properties you want for hand tools; it's not as expensive as stainless steels or super alloys because of the lower nickel and chrome content; and for it to exhibit good corrosion resistance it needs nickel-chrome plating -- so it's just a good fit to the needs of hand tools.

Regards,

A. Hi. There are many screwdriver head styles, but the cross-shaped Phillips has been the world's most popular since the 1940s. There were originally five sizes: #4, #3, #2, #1, and #0. But with the rise in miniaturization, #00 and #000 are now available. The head is not defined by dimension, but simply by the screw size, starting with the #4 designed for screw sizes 18-24 and ending with the #0 designed for screw sizes 0-1. In identifying a screw driver it is also common to give the shank length; for example a #2 x 6 will have a 6" shank length.

Sorry but "2 Phillips 6.0 X 0.8 mm" doesn't mean much to me without context, but I suppose you could be reading an instruction that says to use two (2) Phillips head screws of size 6 mm x 0.8 mm pitch diameter (although that doesn't seem to be the right pitch diameter for 6 mm screws). A 6 mm diameter screw uses a #2 Phillips. Good luck.

Regards,