My Vise-Grip pliers have performed a lot of hard duty over the decades. Many rusted nuts and bolts would still be unremoved if it weren't for their sharp, corrugated locking jaws. I have 10" w/cutter (10WR), 7" w/cutter (7WR), , 7" w/o cutter (7R), , 4" w/cutter (4WR), and 6" long nose (6LN) models. These are all manufactured under the Petersen Manufacturing Company name, before they bought Irwin, who now manufactures Vise-Grips. Even high quality tools eventually show signs of wear after decades of use and abuse. A few of mine had jaws worn down to the point where they no longer would "bite" into the bolt head or nut being clamped.
I was about to buy a couple new pairs of Vise-Grips, but then wondered if I could recondition the jaws to put the pointed shape back on the jaws with a triangle file. Being hardened steel, a lot of times a standard file will barely scratch the surface, but in this case I managed to dress the jaws of four pairs of Vise-Grips before the file (Nicholson 6" double taper triangle) got dull. It will probably dress a couple more if I hunt for sharp areas left on the file. The faces of the file are still good so it's not a total loss. Trading off a $10 file (which had a lot of previous use) for about $50-$60 worth of Vise-Grips is a good deal.
As you can see in the photos, the jaws were clamped in a bench vise and the the triangular file was used to shape the teeth into sharp points. I don't know whether the original "V" groove was 60° as was created with the triangular file, but it is certainly better than the blunt edge.
This Vise-Grip sharpening tip is good not just for performing some preventative maintenance on your pliers, but if you get into a situation where you desperately need a working pair of Vise-Grips for an in-process job, now you have an option. "Necessity is the mother of invention," as the saying goes. My necessity came when trying to remove a drain plug from an oil pan that the previous "professional" mechanic must have put in with an air impact wrench.
Posted December 3, 2018