Hi folks, this is somewhat of a revisitation of an old thread, yet, the opportunity arose to get some new pictures and an example of broken tap removal so I figured it would be worth throwing it out there again.
The folks in the machine shop often present challenges for us over in the weld shop. Intended or not, these challenges are good for learning on the parts of both the machinists and the welders. One of the items that the machinists are given to accomplish involves layout, drilling, reaming, chamfering, and tapping a rectangular chunk of cold-rolled stock. In this particular instance and for whatever reason, the student decided to try power tapping a blind hole as if it was a through one.
Obviously, the results were far from nice or successful. The tap broke and shattered leaving remants of the tip of the tap in the hole and wedged up rather tightly. For this particular challenge the GTAW process was chosen to tackle the removal task and stainless filler was the choice for build-up purposes. I have generally found that stainless filler works really well for both avoiding excessive porosity while welding through tapping fluids/oils and providing a fairly resilient build-up that can withstand a fair amount of torque without re-breaking. Sometimes, however, this process requires multiple applications to come to a successful conclusion, you might only get a small part of the broken tap each time you attempt it. Bolts can be removed in a similar fashion using the same procedure. I know there are many different ways that others approach this situation and as usual I would hope to hear of those(complete with pictures of course) and narratives for the specific steps. Best regards, Allan