I'm about halfway through this build, and just getting started welding it all together. Clay specifies 5160 for the flat spring and W1 for the hammer axle, which I purchased, but he says nothing about heat treatment and they didn't come hardened. Does he just specify having higher quality steel for those particular parts or is it implied that they should be hardened and tempered? I was also planning on forging my eye on the end of the flat spring instead of welding on a pipe, which should be stronger in the long run.  If anything, I'm thinking a quench and good blue temper would give both parts some extra strength and toughness to handle the impacts.

A quench in what? From what Temperature?

Welding the eye is faster and easier. It allows a better bearing and is quite strong enoigh- Clay has built a LOT of these. To my memory, nothing was heat trested short of normalizing the spring eyes after welding, but it has been nearly 20 years so something may have slipped my memory.  I am pretty sure I just used cold rolled for the arm axels.

2 hours ago, jason0012 said:

Welding the eye is faster and easier. It allows a better bearing and is quite strong enoigh- Clay has built a LOT of these. To my memory, nothing was heat trested short of normalizing the spring eyes after welding, but it has been nearly 20 years so something may have slipped my memory.  I am pretty sure I just used cold rolled for the arm axels.

Ok, that's all I needed to hear. John from Black Bear Forge is what got me started on this project, and looking closely at his hammer, he just rolled the spring over like a hinge. I forgot to pick up the DOM tubing the plan calls for and regular pipe would be a little sloppy, so it's either forge it, drill out a piece of round stock, or make a trip and lose half a day. I'll leave the heat treatment stuff out and see what happens - it's not like I can't fix it later. Should be up and banging banging by the end of the week.

Thanks

Good luck. My treadle hammer was a game-changer, even though I used a different design.

I collected parts for my treadle hammer for 5-6 years, then built it in a day. I realized after the fact that I had really over thought the whole thing a lot. 

I went through the same thing.  I did roll the eye around a rod and drifted it to size and then normalized a couple of times.  Frankly, that was over kill.  If you use it and pay attention to the flex, it really isn't that much flex going on.  Mild steel would probably work just fine for a little while.

The hardest part of the build for me was getting the head lined up straight and square with the anvil.  Took several tack it in place, back up and look at it, ect. to get everything rite.

I thought I'd only use it once in a while since I've got a press and a hammer, but it's like having an extra set of hands in the shop.