Welding Tips and Tricks

I have a piece of 1" diameter by 1-1/2" O1 tool steel that I want to forge into a punch. My plan is to weld a piece of thinner mild steel to it as a handle so I don't have to use tongs to forge it. I've read here that a good general filler for tool steel is 309 stainless but I'm not sure how well that weld will hold up under the abuse of forging.

After that I am going to cut off the weld, reweld the carbon steel in a different spot, and heat treat it by quenching in oil. So to sum it up I need a filler rod that will hold up to forging and then either the same or a different filler that I will hold up to heat treating. Or maybe there is a different way to go about it that I haven't thought of. Anyway let me know if you folks have any ideas.

Frankly, I'd go less "heat-intrusive"....

Solder it.

Done carefully, it will make the attachment you need without disturbing the temper of the tool steel, and can be un-done just as easily.

A simple solder joint, even with basic "plumbing solder" will be stunningly strong. It's all about the surface area.

Steve S

I do blacksmithing as a hobby and have run into several tool making that are similar to what you are working on. I'm not sure if the advice that follows is the "correct" way to do this, but it worked well for me when making several spring swages and hot work tools out of 5160.

I preheated the pieces to about 400 degrees to limit cracking as the weld cooled, and then welded the temporary handle on with the MIG welder, using the lowest penetration that I thought would hold. With the preheat, it will probably take less than you may think. The goal was to not go any deeper than necessary to limit admixture or the mixture of the filler will the tool steel. This will most likely not affect the working surface of the tool, as I assume that you'll be welding the handle on a non-working surface.

The heat of the forge will melt anything short of steel, and depending how hot you are going and if water will be used to cool the part as you work (usually not recommended with tool steel), I'd consider avoiding stainless wire.

Just my thoughts and experience, I'm pretty sure a pro would have a better way.

-- Pete

Here's a duro chrome 9/16 wrench, I cracked it by putting a second wrench on it.
I'm going to try and weld it with tig, 1/16 tungsten, and 309l filler rod, and I'll let you know if it holds up.
~John