In Reply to: stuck clevis pin posted by Frank (WNY) on July 26, 2017 at 08:34:14:
You may be looking at remnants of a broken off cotter pin if it appears 'mushroomed' over. Best to try a pr!ck punch first. A 1/8 HSS Drill next but caution as to length of drill -use a stub length because you don't want anything longer that will flex and break off then you really will have problems. The optimum tool would be a carbide drill but you need the workpiece/part solidly secured and a powerful HP drill unit such as a Bridgeport -something you won't get from a hand-held device. If using carbide and the part moves, you will chip or break the drill. Heat is a last option but know that heating steel and cooling down will work harden the material and then make it harder and harder to machine. You will need a heat source greater than a butane or propane torch too; they just don't get hot enough. A welding torch is perfect. Heat it up then use the pr!ck punch, PB BLASTER on a hot surface will cook and probably ain't goo d to inhale...