In The Shop: Related To Wrench Design

Published on: 09:12AM Aug 13, 2011

 It's easy to take hand tools for granted, but they actually are pretty cool, engineering-wise. A lot of thought and experimentation has gone into the tools that we toss casually into our toolboxes. Some of the design considerations are good to know when you're shopping for new or replacement tools. For example:

-There is no functional difference between wrenches that are polished and wrenches that have "sand cast"/unpolished finishes. An engineer with SK wrenches once told me that the only possible benefit of polishing is that the polishing process MIGHT highlight any imperfections in the wrench that could someday lead to breakage, but that those imperfections are usually caught during inspections. He said the biggest difference between polished and unpolished wrenches is simply the price.

-It pays to "play" with wrenches in the store before you purchase them. I once needed an 18-inch adjustable wrench on short notice, grabbed the cheapest one I could find at a local hardware store, and forever regretted the purchase. The cheap price bought me a big, heavy wrench that worked fine, but had a handle that was the same thickness from head to tail. Not only did the "thick" handle add to the overall weight of the tool, but it was so thick that I had difficulty getting a solid grip on the end when I needed maximum leverage. My bargain wrench actually cost me extra money because I eventually found a lightweight 18-inch Crescent-brand wrench with tapered handle that is comfortable to use. Now I have two big adjustable wrenches; one I use a lot, and one that is basically ballast in the bottom of my toolbox.

-Speaking of weight, I'll never buy another pipe wrench larger than 12 inches unless it has an aluminum-alloy handle. Our shop has a steel, 24-inch pipe wrench we use to hold arbor bolts on disk gangs. I'm barely man enough to lift it off the peg in the tool room. One of the other mechanics has his own 24-inch pipe wrench made from an aluminum alloy, and it is much more user-friendly. The only problem is price. Aluminum alloy wrenches are expensive. If you see a pipe wrench with "aluminum" handle advertised for a reasonable price, assume that the handle is poor quality aluminum. My experience is that high-end aluminum handled pipe wrenches are pretty pricey, but extremely durable and well worth that price. I've got a 16-inch aluminum-handled pipe wrench and can testify that it withstands not only a 3-foot-long "cheater" pipe, but more than occasional "tapping" with a 32-ounce hammer to help break loose stubborn nuts and fittings.

I'll continue this discussion of tool design sometime in the future. So many tools, so little time...