EggHead1954

I spent the past 25 years working in the metal working trades so know a little of metalurgy. First off, most hammers are not that hard relitively speaking so chipping is unlikely. Second, if they are hard enough (and I would say too hard for the purpose they serve) then your safety glasses should protect you. What? You don't wear safety glasses? Well then, shame on you. Typical carpentry/woodworking presents enough hazards to warrant wearing them. Do you really care whether you lose your sight to a wood piece or a metal piece?

Aside from all this, you'd have to hit the two hammers together pretty hard to create a chip and likely it would not occur on a single blow but after a fair number of strikes. Me? I'd just settle for the proper tool. A steel centre punch. But still wear those safety glasses.