Defective Buck Bros 1/8" Gouge?

[Patrick Chase]

Adding one little detail to George's impressive writeup... If you want to correlate temperature to surface color, see this (or any of a bazillion other basically identical pictures on the Interwebs).

He's telling you to aim for brown, which is ~480F. If you refer back to the O1 tempering chart I posted in #8 that would get you Rc60 for properly hardened O1. He told you to stop no higher than dark blue, which would get you Rc58 or so in O1.

IIRC the shape of the curve is similar for other HCS - George, is that right?

[Stew Denton]

George,

Thanks you! One more note of thanks on this, I definitely learned from your post. I also appreciated Warrens comments.

Uneven heating and uneven color change is a problem I have had, particularly with smaller items when using a butane torch to temper. It has been a problem for me where you have thicker steel tapering to thinner sections. I have typically tried to heat the thicker area first and more, but sweeping quickly every now and then over the thinner areas. I try to be very patient and slow in the heating, try to keep the color change even all over, and let the heat work it's way from the thicker to thinner as much as possible. Even so, keeping the color changing in a consistent way has been a problem for me.

Like Fred and others have mentioned, I have been able to do this to where I end up with a usable tool, at least usable for me as a hobbyist, or one who works for free on stuff for kids and grandkids. However, in the cases I am writing about above, I have never done what I would call a "masterful job" by any stretch of the imagination. Also like Fred stated my tempering is certainly "not up to engineering standards", and being partially color blind does not help me with this either. But again, if I got a usable tool from the effort, even if perhaps not perfectly done, which certainly beats having one that is useless.

This sort of post is what makes this site so neat to read, guys like you, Warren, Jim, and others as well, write things that I might never learn any place else.

Thanks again and regards,

Stew

[george wilson]

I did some quick Googling of color charts before answering Patrick's question,to see where he is getting some of his information. I do not need to refer to them myself,being in toolmaking at the down and dirty level for practically all of my adult life. Even back in the 1950's,I was doing some tool making for myself,always being short on money.

Frankly,I don't understand the chart with colors and RC hardness as put out by "Anvil Fire". It lists 58 RC for 1095 at a full dark blue color. That just is NOT TRUE. I think a lot of these guys are at the HOBBY LEVEL,putting out info of that kind.

I KNOW that cannot be correct since we bought full blue 1095 sheet for making our saws. It ALWAYS tested on our Versitron,fully calibrated with sample test blocks,at 52 RC. Which is a fileable(if a bit hard on files!)RC hardness. This will be an o.k. hardness for small carving tools,though I'd really like them to be at more like 55 RC. I say that 52 for small carving tools would be o.k.,because they usually aren't cutting a great deal of wood,since they are generally for smallish details.

So,if you can manage it,I recommend a dark brown,and no higher if you can help it. Remember I have said that the ANTIQUE plane irons I used for many years(and still do),could BARELY be scratched with a NEW,FINE CUT NICHOLSON FILE. This is PRE MEXICO,of course! So,they were probably 54 or 55 RC. I had no hardness tester when I was the musical instrument maker. But,later experimentation with the Versitron bore out this assumption,and made it FACT.(I am always a great experimenter. Always curious about many things).

I am pretty safe in assuming that ANTIQUE carving tools will be W1,and not 01. So bear this in mind,please,when looking at color charts. And remember,I work from experience,NOT from Google. There is so much BAD INFO out there,I wonder how the newbie ever gets anything straight. It seems to me that every girl out there wants to be a jewelry maker or a photographer,and every boy wants to be a blacksmith!(O.K.,I know that is really not 100% true. Just the way it seems AROUND HERE!)

[Patrick Chase]

I did some quick Googling of color charts before answering Patrick's question,to see where he is getting some of his information. I do not need to refer to them myself,being in toolmaking at the down and dirty level for practically all of my adult life. Even back in the 1950's,I was doing some tool making for myself,always being short on money.

Frankly,I don't understand the chart with colors and RC hardness as put out by "Anvil Fire". It lists 58 RC for 1095 at a full dark blue color. That just is NOT TRUE. I think a lot of these guys are at the HOBBY LEVEL,putting out info of that kind.

Yeah, that's why I picked a chart that didn't have Rc values. I'm not sure where you dug up the "Anvil Fire" one or why you bering it up in your reply, because it certainly didn't come from me.

The color->temp corellations are very well established, though, are they not (modulo slight variations due to composition)? Those are determined by interactions of Fe-oxides and and oxygen...

[Pat Barry]

Which brown is George talking about? Dark Yellow Brown or Brown Red ? There is a huge difference. It must be the Dark Yellow Brown that comes right after Golden Yellow / Dark Straw. At 480F you could do that on a stovetop pretty easy

[Don Orr]

Wow-another EXCELLENT discussion/education on treating steels. Thanks George-your knowledge is vast, your generosity boundless. I never would have thought to use a steel plate for even heat distribution on the stove-brilliant! Not that the boss would ever let me do that though. I used a toaster oven to temper an O1 plane blade that I made. Put the blank in after hardening, set it to 450 deg, waited about a half hour and turned it off. Came out a beautiful dark straw color. Sharpened and honed and it cut great. It can be done at home with a little guidance from the experts. The steel does need to be clean and shiny to see the color changes.

[george wilson]

Dark brown is just dark brown as far as I'm concerned. It starts out golden,then light brown,then a darker brown. Never noticed any red about it.

Yes,different alloys show different colors at the same temperature. You need to be careful what alloy you're using. Don't use junkyard"Mystery metal".Most guys use 01. It is a good all purpose,fairly easy to harden and temper tool steel. W1 steel will harden harder than any other steel. It goes up to 67RC. It also will get SHARPER than any other steel(I don't know about powdered steels. My LV PMVII block plane blade gets mighty sharp!) The steels I have used are W1,01,A2(ALWAYS for my wife's punch and die sets. It stays sharp longer,and does not noticeably distort due to being air hardening.,ATS 34(a complicated steel to deal with!), D2(a high wear resistant tool steel made for shearing other steels. But,it doesn't hold a razor sharp edge. The edge wears off,leaving the edge just under razor sharp,but very long lasting. Best for punches and dies rather than knife blades).And lastly 52100 ball bearing steel. It is a pretty simple steel,with high carbon and 3% chrome. BUT,I think a pocket knife blade I made for an antique pocket knife whose main blade was too worn down may be the very best blade I ever made. It gets VERY sharp,and STAYS VERY sharp for a LOOOOONG time! A bit of trouble to harden,as it decarbs badly unless you wrap it in stainless steel wrap while at high heat. At first,I did not think much of this blade,but,having sharpened it several times,it now holds a terrific edge. I must have let a bit of air get to it when hardening,and now have gotten through the softer skin. Possible for the stainless steel envelope to leak a bit. I have a big bunch of large ball bearing BALLS that I have to weld onto a steel bar,then pound into a strip for making knife blades. I keep the temperature at not more than RED heat. Doing that causes the carbides in the steel to break down into very small particles,enabling very sharp edges to be had. Over heating it will melt the carbides,and they condense into large formations,causing less keen edges to be had. You need a POWER HAMMER to pound a red hot ball into a strip! Red hot bearing steel is about as hard to forge as cold mild steel.



Patrick,Anvil Fire had nothing to do with you. It was just a chart which I noticed had BOTH colors and RC values. Pretty inaccurate though,in my experience. And NO,I'm NOT going to appear on that silly "Forged in Fire" program with that bunch of clowns. That includes the judges.I wonder if guys like those made up that chart!! (Not that anyone asked me about being on that program. I am aware that a LOT of the more DECENT knife makers refused to go there because of the rules they have to sign up to follow.) The ones they are getting certainly aren't what I'd call "experts" by any means. I don't know WHY they always want the contestants to make such LARGE knives. They are not useful for anything. Except the MACHO factor!! I'm not really a knife maker anyway. I make one every now and then. But,I think you have to be willing to work for very little an hour to make knives for a living. I think most of these guys I see at gun shows must have other day jobs.

Don,even professional tool and die makers use a toaster oven. Me included. But,I don't trust the little cheap thermometers that they come with. I use a LONG probe high temp. thermometer from Brownell's Gunsmith Supply. I carefully slip it into one of the vent slots on the back side of the oven. Having a PRE HEATED oven to put your quenched tools into AS SOON AS YOU CAN BARELY HANDLE THEM(that's about 140º) is an excellent rule to follow. You get better performance from your steel. PLUS,hard as glass tools left laying about until it was CONVENIENT to temper them HAVE been known to suddenly burst violently. Fully hardened steel is full of stress.

[Don Orr]

Thanks for the extra info George. I didn't trust the thermometer in the oven either but it was what I had at the time. Kinda scary about exploding steel-that could ruin a good day for sure.

[george wilson]

ALL of you need to be careful about leaving fully hardened steel around. First,it is not good for the ultimate performance of the cutting tool(if it is a cutting tool,punch and die set,etc.)

The MOST DANGEROUS situation is when the steel in question has a lot of mass or thickness to it. a 1/8" chisel is not too dangerous,but it should be tempered AS SOON as you can barely hold it in your hand. Then,it will stay sharp longer.

If your item does go POP!!!!! it MAY send high velocity fragments flying.