Its is simpler to build up the bearing surface of the bolt than to weld up and re cut bites . It may well be that the bite has worn and will need to be "dressed " but this is usualy only a matter of filing it to even out any steps or exessive wear on the leading edge . It is rare that the amount of wear will so great that this needs much work . It is of course a matter of experience in getting the built up bolt dressed correctly and so is getting the two surfaces to bear correctly so that as the bolt closes or goes home that the pressure of the bolt is not to great but has the maximun surface area in contact and as with any wedge the maximum grip will be attained when the bolt is fully engaged .
