No 4 & No5 Bolt Heads (Update)

[Peter Laidler]

The PLAN size of the length of the bolt heads are
No3 - 0.638" -.002"
No2 0.635" -.002"
No1 0.632" -.002"
No0 0.629" -.002"

You can see that even from this, if a, say, size 3 is made to the drawing spec, then it COULD easily be 0.636". As I said, we didn't take much notice of the number but might use it as a bit of a rule of thumb guide. Same as Bren or L1A1 locking shoulders