Lug nut /stud length

Thanks all.

Mil-spec is best and b/c I am buying new studs I Will actually go 2.25 to 2.5 the stud dia b/c the nuts are 1 inch long and I want a minimum of 1/4 inch of stud extension beyond the top of the nut.

I only meant that 1x the diameter, which I have now, is considered the minimum safe engagement. But it ain't staying that way............