December 7, 2000


What type of steel is used to make crampons?

Here's a question you probably don't get very often. I'm making some crampons for my rock shoes for a trip to Patagonia. Eliminating plastic boots will save much weight. I have a design I believe will be very effective; I'm addressing insulation/warmth issues as well as support issues. I've made prototypes out of aluminum. Of course I will test the finished product extensively before trusting my life to them. My question is, what steel alloy should I use, and where can I get some?

— Dan Aylward Seattle, Washington

Uh-oh. Fanatic alert! I'll grant you that boots are heavy, but by the time your new crampons are finished and you deal with the insulation issues, do you really think you'll be that far ahead, weight-wise? Not to mention the fact that plastic boots are built to take the torque and leverage of a pair of crampons, whereas rock shoes really...aren't.

But, what the hell, I'll play along. In fact, I called Kevin Slotterbeck, the design engineer for Seattle Manufacturing Corp., better known as SMC, a long-time maker of crampons and other mountaineering equipment. SMC's crampons are made from 4130 steel, an alloy of chrome, molybdenum and carbon. It's pretty common stuff —- ask any metallurgist about 4130 steel, and he or she will be able to discourse on it. Anyway, the metal is heat-treated to particular specifications, then a "secret" (so says Kevin) step is taken to prepare it for use in crampons. The good news: You can buy the steel in the states, as SMC does, and in fact many factories will happily sell you a sheet or two. The bad news: Your UPS guy might not be happy —- one sheet will weigh at least 700 pounds.

There are other problems. Aluminum is a pretty soft metal, and easy to work. Cromoly steel is not. SMC and other crampon makers use a metal stamp to cut out the rough crampons. It's a 75-ton stamp, designed to shear in two directions because it's otherwise quite difficult to stamp steel to a reasonably good point, which crampons need, of course. Then you'll have to figure out a way to bend the stuff into shape, finish the points and so on.

But there you go. Order up some 4130 steel, build a 75-ton stamp in your garage, design and fabricate a die to cut it, and you're in business. And you've got a standing order from me to buy a pair at the going rate for most crampons—$100 to $150.

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