I wish to build a spring swage that fits in a hardy hole. i find that sage advice is the best advice. Any tips?  Is this something that can be made in a scrap yard? should I buy materials online? What's a good type of spring steel? You know, the basics.

I do not discriminate by level of "sage"

Are you making a swing arm swage or a bent spring swage?  For bent spring swages I generally use coil spring from cars and trucks. Not knowing where you live I can't say where the best location to source the material needed would be.  If you can buy drops from a spring manufacturer I would go that way; but most can't and so I use stock from a scrapyard.

5160 is a good alloy for it; please be sure to heat treat appropriately!

I made mine from 1/2" mild steel, probably ~ 20" or so. I flattened ~ 5" toward the middle of the bar to 1/4 to 3/16", curved it to a ~270 degree arc, and adjusted so the remaining round parts were ~parallel and spaced 1/2" or so apart. I then welded that to a piece of box tube that fit the hardie hole. The flattened part acts as the spring and the round parts are the fuller. Hope that made sense. It was a quick and easy beginner project, and it's still in use.

Steve

The Bent spring would be best, I even have coil spring steel 

how should it be treated?

Correct for exactly what you will be using it for.

I used coil spring and pretty much did exactly the same as Stash except for the amount of material used since I did use could spring instead of mild. I left mine without any heat treatment just normalized after forging and welding and called it good. 

I made mine from a 1/2" dia. sway bar (probably 5160 or similar). Like Stash, I flattened a section, but in my case, it was to double up to fit in the hardy hole. Normalized, no other heat treat. 

Works great. 

 That's way simpler than I was thinking in my head. I guess I tend to overthink things, that looks easyer than the image in my head. Thanks Xb

Keep in mind that these photos are technically of a spring fuller, not a spring swage. A fuller has convex surfaces that create concavities in the workpiece, while a swage has concave surfaces that shape the convex surfaces of the workpiece.

Greetings Paradox, 

.        I have my beginning students make a spring fuller and a couple of bending forks,. Notice the bends in the fuller they fit the hardi better and the rised bend works as a edge guide for the spring top. Ya never can make enough tools .. Have at it and good luck. 

Forge on and make beautiful things 

Jim

I love the curls those are beautiful.  This looks like a easily adaptable tool. I have a discount with my local scrap yard and can practice all day. When I'm not at work