My welding teacher told me I was ruining my hammers - and he was right

Last week at the Denver guild meetup, a 70-year-old welder named Hank watched me grinding a finished hammer head and just shook his head. He said I was burning the temper right out of it with aggressive grinding, making the face way too soft for real work. After testing 3 hammers I made the old way against one I hand-filed instead, the filed one held up 4 times longer on a steel plate. Has anyone else gone back to hand filing after relying on power tools?

3 comments

3 Comments

fisher.jessica12h ago

Why is everyone so sure a file is actually better here? From what I can tell, hand filing creates a ton of friction and heat too, especially if you're bearing down on a bastard file for twenty minutes straight. Unless you're dipping that file in water every twenty seconds, you're still generating heat that could mess with the temper, just slower. Plus, a file leaves a rougher surface that needs more lapping or polishing anyway, which adds even more time and heat. Wouldn't it make more sense to dial in your grinder technique like the_riley did, using water and light passes, instead of pretending a file is some magic cold process? Seems like people are romanticizing hand tools when the real issue is just knowing how to manage heat, not which tool you grab.

blairm7714h ago

Hang on, gotta call a small thing out here. Hand filing is definitely better than burning the temper with a grinder, but a rough bastard file still heats the metal some, it's not magic. I've messed up a few chisels by going at them too hard with a file, especially if the steel is already thin from heat treat. The real trick is keeping it cool with water or oil every few passes, and taking your time. Your teacher was spot on about the grinder, but don't think a file gives you a free pass to be sloppy either. A cool cut is a good cut, regardless of the tool.

the_riley13h ago

I've been testing this exact thing for six months now, and my grinder-finished hammers actually outlasted the filed ones by about 15% on mild steel. The trick for me was using a variable speed grinder on low with light passes and dunking in water every ten seconds, which kept the face under 150 degrees by my temp gun. Hank's advice is solid for aggressive grinding, but with the right setup you can get a better finish faster without losing hardness.