Things That are Made of Ductile Iron

Posted on 13 December 2016

According to the Cast Metals Institute of the American Foundrymen’s Society:

Pipe (about 44 percent of all ductile is used in pipes)
Valves and pipe fittings
Automotive front wheel spindle supports
Steering knuckles
Disc brake calipers
Engine connecting rods
Idler arms
Wheel hubs
Truck axles
Many suspension system parts
Power transmission yokes
Turbo housings and manifolds
Oilfield equipment, including high-pressure valves
Gears for automotive, farm and construction machinery
Hubs and structural parts for wind turbines
Plus lots of military uses that are not openly discussed

Oh and don’t forget that Lie-Nielsen and Veritas make handplanes from ductile iron – that’s why the tools don’t break when dropped off a building.

After researching all the things made using ductile iron, we were sure it was no problem to make a holdfast that would last. Many ductile components are designed specifically for stress-loading, so a mallet strike isn’t going to hurt ductile.

Still, we had to be sure. So after we got our first casting back in April 2016, I spent a day setting and releasing the holdfast with a 2-1/2 lb. sledge. I’d hit it until I got tired, do a little editing and then go back to hitting the holdfast.

That first holdfast is still on my bench and gets hit every day.

The Crucible holdfast is available in our store for $135, which includes domestic shipping.

— Christopher Schwarz

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  • Richard: January 20, 2017

    Is Crucible still alive? No updates in a while….hope everything is ok.

  • Christopher Schwarz: December 14, 2016


    No we do not. It’s just not necessary for this tool. (It’s a very cool process, however!)

  • Michael Keller: December 14, 2016

    Not to get all pedantic, but do you guys go through a heat-treatment/tempering process after casting? Austempering can really improve the dynamic and fatigue properties of ductile cast iron. The process might screw with your tolerances though.

  • Scott Stahl: December 14, 2016

    " I’d hit it until I got tired, do a little editing and then go back to hitting the holdfast."

    You should have turned that into “The Anarchist’s Workout Video”.

    If I had the time, I’d photo edit your mug on a Jane Fonda 80’s workout pic for effect. :)

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