Thread: Forged razor out of 1084 not performing as well as I hoped trying to figure out why

So austenizing at 1500 should get you about 65rc as quenched, tempering at 400f should be in the 60-61rc area (I’m referencing Kevin Cashen’s website). Maybe your low rc is due to making the edge too thin before ht? ie., losing heat on the way from kiln to quenchant?

60-61 should work just fine at the angles we hone razors at, as I understand it.

Originally Posted by jfk742

Maybe your low rc is due to making the edge too thin before ht? ie., losing heat on the way from kiln to quenchant?

Entirely possible. I did grind it fairly thin before heat treat, definitely thinner than the usual 'thickness of a dime' recommendation. It did hit the oil quench within 5-10s of getting out of the kiln though. A good possibility is that the tempering temp was too high, I believe the small toaster oven hit as high as 450 at points, and with the ah, lack of stability in terms of the tempering temp, that could be another cause.

Is there any issue that you know of with letting a blade sit at room temp for say, 2 hours or so before tempering it? I'm thinking if I can wait for my digitally controlled kiln to cool down from the 1,500 F annealing temp, I'd have a lot more luck with getting an even tempering temp.

I would say go to the thickness of a dime or a little more, it will also help with warping, and then get it to the quench as fast as possible. You’ve got to beat the nose, from 1500f to 1000f in less than 2 seconds if I’m reading the graph correctly. At 400f you can take it out and let it air cool from there to room temp, should give you enough time to cool the kiln if you leave the door open.

You may want to send a pm to bruno, bluesman7, or spazola. The 3 of them have a ton of knowledge. If you do, report back to your thread, as we all like to learn.

Originally Posted by GuyMontag

That is very handy, thank you!

It looks like my blade is waaaay too wide. I'll have to see if I can grind it down into something workable or just make another one - practice makes perfect!

Also the width of the razor should be even along the length. Your razor seems much wider at the heel than at the toe.

Originally Posted by GuyMontag

Entirely possible. I did grind it fairly thin before heat treat, definitely thinner than the usual 'thickness of a dime' recommendation. It did hit the oil quench within 5-10s of getting out of the kiln though.

I'm sorry, 5 to 10 seconds? Did you have coffee first? I know knives let you get away with that sort of thing because they have a lot of thermal mass.
.
that is much too long. I try to keep this time as short as I possibly can: out of the kiln and into the quench in 1 fluid motion that takes a second or so.
A razor has a very low thermal mass. Especially if it is already much thinner than is good, I can pretty much guarantee that this right here is your problem.
A razor's edge works like a thin cooling fin. By the time you hit your quench it was already far too cold.

Originally Posted by GuyMontag

Is there any issue that you know of with letting a blade sit at room temp for say, 2 hours or so before tempering it? I'm thinking if I can wait for my digitally controlled kiln to cool down from the 1,500 F annealing temp, I'd have a lot more luck with getting an even tempering temp.

None whatsoever in terms of end result. The only risk you run is with san mai blades that have a lot of stress in them after quenching.
If you leave those sitting for 2 hours, there is a good chance your razor will become 2 pieces

Subscribed....this is really interesting stuff....im sorry i have nothing to add but im here to learn!

You have received some pretty good info here.
The general rule is that 4:1 ratio of blade width to spine thickness. Greater than that and the edge crumbles while honing because it has lost carbon while heat treating and it is to thin while honing.

Use a meat thermometer inside the toaster oven to set the desired temp.

You have about 1 second to go from the forge/kiln to the quench. Practice/adjust your setup/layout before you start

The edge of the blade should be about the thickness of a dime or more before heat treating. It means more work while finish grinding but you get better steel as an end result.
and you avoid the "potato chip" edge.

Just my 2¢

Originally Posted by Bruno

Also the width of the razor should be even along the length. Your razor seems much wider at the heel than at the toe.

It was before I realized the edge was too thin and was crumpling like foil I ground it back to the point where it was an even thickness the length of the blade, even if the aesthetics were shot by that point. It could be salvaged with more hollow grinding, but between the handle being too heavy and the tempering leaving it softer than I wanted at ~58 Rockwell, I'm just going to make another. I've got enough 1084 for at least several more, doesn't hurt to practice. Going back to forging after years of stock removal is a complete head trip in some ways, definitely will take some getting used to.

Originally Posted by Bruno

I'm sorry, 5 to 10 seconds? Did you have coffee first? I know knives let you get away with that sort of thing because they have a lot of thermal mass.

Might have been less, I had the bucket of oil in front of the kiln, aside from a brief fumble gripping it with the tongs and not touching the kiln with my soft, delicate human flesh, it was fairly quick. Given the 1 second ideal mentioned earlier, it won't hurt to practice a bit with the kiln cold. Some box jaw tongs vs the flat tipped ones I have now would probably also help with getting a good, accurate grip quickly.

I received an email reply from Kevin Cashen about how long you can wait between quenching and tempering, it sounds like the ideal wait between quenching and tempering is "as soon as the blade is comfortable to hold", but if your only (reliable) heat source won't be at the right temp for a few hours, doing a snap temper by quickly bringing the blade up to 275 F, then letting it cool can keep the stress levels down until the conditions allow for a longer tempering cycle.

Make sure you come to Charlie Lewis Texas razor meet next February. About 10 miles north of Wichita Falls.

You will have fun.

Originally Posted by randydance062449

Make sure you come to Charlie Lewis Texas razor meet next February. About 10 miles north of Wichita Falls.

You will have fun.

Randy speaks the truth here. Guys will stumble over themselves to help someone along. As you have learned already, knives are much easire than razors.

Question? Do you shave with straights?