One Blacksmith’s Perspective on Holdfasts
It is simply astonishing how some commercial holdfasts are both ineffective and prone to self-destruction. It really is no wonder that woodworkers have switched over to some other sort of work-holding device , a shoulder vise, the Veritas Wonder Dog, even simple wedging. All are more effective (and robust) ways of securing work to your bench.
After destroying our cast gray iron holdfast (and digging up the stories of dozens of other woodworkers who have done just the same thing), we decided we had to investigate the metallurgy side of this historical and essential jig. Soon we’ll be traveling down to the workshop of bodger Don Weber, a blacksmith, coppice woodworker and builder of Welsh stick chairs. Don’s going to make us a couple holdfasts from wrought iron, a material he says is ideal for this task.
Our most excellent set of holdfasts we’re working with now were made by blacksmith Phil Koontz in Galena, Alaska. Here’s what Phil had to say about the materials:
“They are mild steel; cold rolled 11/16″ round bar stock. Using 3/4” steel would work too, but I use a smaller size just in case the holes in someone’s bench might be too tight. The functional difference between cold and hot rolled steel seems to be the finish. Cold rolled doesn’t come with the yucky black oily coating like hot rolled. It may be because they are an odd size and surface ground, but the steel I use has a shiny finish that I have to get rid of before I sell the tools.
“I’m sure wrought iron would work fine, but it’s very much a luxury item for smiths these days; and I stay away from spring steel or high carbon steel just to be sure it doesn’t develop flaws that will pop up someday in the future…¦. And I would say that any smith of very moderate skill could make them easily.”
OK, so we know that wrought iron and mild steel are good materials. But what about malleable iron or ductile iron (sometimes called “nodular”)? These are cast products that are designed to take a beating. I’ve seen plane bodies made using ductile that were beat by a sledgehammer and they we’re merely bent. Looks like we have some more investigating ahead of us.
– Christopher Schwarz