I made two punch tools last week and each was dedicated to a small project. I’ve mentioned my affinity for making dedicated tools, jigs and templates which are stored as a group related to each repeated project. In these cases each punch had a round taper to make a 3/16” hole. I made each of them from one half of an engine valve shaft and welded a short utility handle.
I have used this valve stock for quite a while to make chasing tools and drifts and have been impressed how well they hold an edge and shape. I always thought there were some variety of stainless steel which was air hardening until I found the article below. I’ve never had to buy any as the auto mechanics seem to be quite free with giving used ones away.
I made one punch just by grinding on a zirconium sanding belt and the other by torch heating and forging the taper and then grinding to finish. I keep a batch of utility handles ready to use so making the punches and welding the handles took a total of about 5 minutes maybe ten if I count the time spent stamping the names on the handle labels. That seems like a good investment for tools which I anticipate will last for years.
Nice reference about engine valve alloys:
http://www.enginebuildermag.com/Article/2564/valve_alloyswhat_makes_them_so_special.aspx
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