Originally Posted by
Mark V8
Random thing I actually remember from college in the 1980's
That's the engineer in you also other types of bolts have markings on the heads to denote what hardness they have.
It's been so long since I done my engineering apprenticeship 🙄 in fact about 24 years ago.
Last edited by costina; Aug 23, 2018 at 09:54 PM.