# Heat Treating W1



## HBilly1022 (Jan 14, 2018)

I want to make some small boring bars, using some 1/4" W1 drill rod I have on hand and was intending to heat to non magnetic with a propane torch and then dunking it into water. Will that work or am I wasting my time? I could also fire up my wood burning forge for heat but the torch would be simpler and faster. Could even put the piece into the wood stove if that's a possibility. If none of this makes sense I guess I will just do it the smart way and get some HSS blanks.


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## Dave Paine (Jan 14, 2018)

That should work to make it hard, but it will also be brittle.    Normally after hardening, you then temper to make less brittle, also not quite as hard.

An example site showing tempering temperatures vs hardness.

W1 hardening/tempering data.

I have O1 around to make tools.   I use the oven for tempering.    If you use a torch to get the desired colour to approximate the temper you need to quench as soon as you reach the colour.   In your case quench again with water.


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## BGHansen (Jan 14, 2018)

Flame hardening will work fine.  Just make sure to hold the part at orange for a few minutes (at 1/4" it'll be heated through to the core pretty easily).  Dunk in water as you suggested.  As Dave mentioned above, you may look at tempering the part after hardening as it'll be brittle. 

I attached a color chart for tempers of steel which you can carefully do with a torch.  Start by cleaning the part with emery cloth so it's shiny.  You have to be really careful as too much direct heat will make the colors change quickly.  I've flame tempered by heating a plate with the part setting adjacent to the heat.  I currently use a Thermolyne 1900 hot plate for tempering.  It'll heat up to around 700 F and can be had used off eBay for under $50.

Bruce


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## mikey (Jan 14, 2018)

HB, your post reminded me of my very first boring bar that I ground from O-1 steel. I turned it carefully, ground the cutting head so it was a thing of beauty, heated it to non-magnetic and dipped it in oil. So far, so good and it was file tested to be hard. I didn't know how to temper back then but I figured hard is good, right? Then came the big test - a bore in aluminum. As soon as the tip of the cutter touched the material the head snapped right off - ping! This is how I learned about the need to temper such tools so I'm with Dave and Bruce.

I use a $25.00 toaster oven with a glass door so I can see the color change. Most small tool steel parts can be tempered easily in such an oven. When you get the color you need you can pull the part and either quench it or let it air cool and the result will be the same, a tempered tool that won't snap off the minute you stress it.


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## HBilly1022 (Jan 14, 2018)

Thanks guys!

I did the heat treat and the part is definitely hard. The file just skates across it. I wasn't going to temper but after all of you say it is a good idea and especially Mikes story of the head breaking off, I figure I better do that.

I've got an old toaster oven buried in storage somewhere. The wife wanted a new one because this one was old and looked like it too but it worked and I couldn't bring myself to throw it out. Now I finally have a use for _one_ of the "_valuable_" things I saved. lol.

Dave, thanks for the link.
Bruce, thanks for the chart.
Mike, thanks for saving me from breaking my first one, lol.


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## T Bredehoft (Jan 14, 2018)

Just a note, I learned early on, when working with O1, before tempering, after polishing to bright steel, cleanse the part of all oil. Otherwise the oil will turn color and give the appearance of "light straw" or "dark straw" or what ever you are aiming at.  I found a quick shot of Steel Ink Remover was ideal, but alcohol or dishwashing detergent followed by clean water worked just as well.


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## Ulma Doctor (Jan 14, 2018)

+1 on the toaster oven-
i found a brand new one with digital heat controls for $12  at the Goodwill Store
the actual temp is within 10°F of the displayed temp, which i thought was very good


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## gi_984 (Jan 19, 2018)

Ulma Doctor said:


> +1 on the toaster oven-
> i found a brand new one with digital heat controls for $12  at the Goodwill Store
> the actual temp is within 10°F of the displayed temp, which i thought was very good


Mike, how do you check the temp against the displayed temp?  IR heat gun or pyrometer?


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## Ulma Doctor (Jan 19, 2018)

gi_984 said:


> Mike, how do you check the temp against the displayed temp?  IR heat gun or pyrometer?



I have a temperature probe for the fluke meter


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