I had my tool engraved with Dremel machine... SImple inititials nothing fancy and it didn't void a warranty at all. Well I had a hard time exchanging it at the store when my screwdriver broke but manager very quickly came to his senses. I was told that you can do whatever you want to the tool as long as you don't interfere with main parts. So if you engrave the handle and tool snaps at the engraving than it's your fault but if your pliers breake than everything is fine. Too bad that my engraving didn't protect the tool from being stolen