Richie's Mk1 Restoration

[Richard Farrant]

Originally Posted by eddy8men

there's been a few discussions on the "chisel marks" on armour plate some of the ideas were, descaling or hardness testing. do you know for a fact shaun that it was straightening ?

eddy

Eddy,

You will often find these marks on hull plates that have apertures cut into them for ports, etc. During the heat treatment process, distortion can occur and the hammering is to relieve it. It is definitely not hardness testing, that is done more accurately, by grinding a small part of the surface and then doing the Brinell test or similar, where the surface is indented and the depth of indent is measured to ascertain the hardness.