[Mike Blue]

The 5xxx series, which includes 5160 and 52100 have chromium in them. Chrome is notorious as a carbide former. But, the excess carbon/carbides will dissolve if you're at the right temperature and anticipate soaking a little longer than might be normal for say a 10XX steel. That way you can get maximum performance out of a tricksy steel because you're quenching from maximum carbon input rather than partial.

Those pesky little minor alloying elements don't have to be present in large quantities to make big effects. Steel is a good teacher. Sometimes good teachers are pains in the butt-ocks.

[JoshEarl]

Originally Posted by Mike Blue

The 5xxx series, which includes 5160 and 52100 have chromium in them. Chrome is notorious as a carbide former. But, the excess carbon/carbides will dissolve if you're at the right temperature and anticipate soaking a little longer than might be normal for say a 10XX steel. That way you can get maximum performance out of a tricksy steel because you're quenching from maximum carbon input rather than partial.

Those pesky little minor alloying elements don't have to be present in large quantities to make big effects. Steel is a good teacher. Sometimes good teachers are pains in the butt-ocks.

O1 is another one with some chromium, which kind of ties this thread in with another discussion we've been having.

Josh

[Twalsh341]

Originally Posted by Philadelph

Thanks Josh. That starts a nice explanation for me. Do you use bar for stock removal? That's basically what I think I'd get into for now. I'm having a tough time finding carbon steel stock bars though. Stainless is on all the knife supplies places, but that's most of what I can find besides Forging steel. I found O1 which I actually knew about since I read your thread about it.

Start with a simple high carbon steel 1075 or higher in the 10xx series, or W1 I love W1 for my carving tools, it responds a lot like 1095. simple water quenching steels will be easier to use than exotics (stainless) for the beginner.

[mastermute]

Have anyone tried AEB-L? It's supposed to have a fine grain and is said be for cutting applications e.g. knives, razorblades and scalpels (sounds ideal for what we are doing, doesn't it?):

UHB Stainless AEB-L offers sharpenability and edge retention that satisfies extremely demanding requirements. UHB Stainless AEB–L is a hardenable stainless steel with an ideal chemical composition that ensures good results in blade production.

Also found this:

1905 - The first cold rolling mill was ready for production, first deliveries to Gillette, USA

(It's not about AEB-L but about Uddeholm strip steel. Cool to see they used Swedish steel )

[Mike Blue]

AEB-L is the Uddeholm equivalent of 12C27 from Sandvik. Forgeable stainless steels and very good for knives/razors I would suspect.

[RobertFontaine]

Is there a reason razor makers don't use commonly use 440?

[mastermute]

Originally Posted by RobertFontaine

Is there a reason razor makers don't use commonly use 440?

I have looked around a bit and found that 440C/AEB-L/12C27 are considered to have very good "edge holding" proprties. I don't know the reason why they aren't used for razors.

[Mike Blue]

The 440 series has typified the problem with either a blade is too hard and not tough enough, or too tough and not hard enough. I've seen vastly more broken 440 series steel blades in my life than any other steel and especially in thin blades. Either way it also got a reputation as hard to sharpen.

[randydance062449]

To answer one of his questions... just purchase some flat bar stock steel, 1/4" x 1" or 1 1/4". I purchased 1095 stel from Admiral and from 3 6ft lengths I cut 30 7" razor blanks a few days ago.
The heat treating for 1095 is a bit picky and do not use water as a quench or you will learn what a cracking blade sounds like. Use a fast oil as a quench. I will be posting about how Parks 50 quenching oil works in the near future.

I finally finished building my grinders and now have them at home. Now to set up my workshop here and finish grinding some razors I started last year!

[JoshEarl]

Randy,

You'll love the Parks 50. It has made heat-treating seem rather uneventful, which is good but a little boring... There are no flame-ups and very little smoke. It almost seems more like rinsing the blade off than quenching it. Cracking has been a non-issue so far for me.

Josh

[L R Harner]

i have parks 50 also and it great stuff. i cover all my oil hardening stuff (slow oil steels i interrupt the quench) that and the Al plates for quench of air harding steels is mostly uneventful

tho i did warp 2 razors the other day in 1095

[Russel Baldridge]

Originally Posted by randydance062449

The heat treating for 1095 is a bit picky and do not use water as a quench or you will learn what a cracking blade sounds like. Use a fast oil as a quench.

While a fast oil is solid advice, heated water is not out of the question. I've only broken one out of ten razors made of 1095 that were quenched in water. And in fact the one that broke, should not have, it was my fault.

But then again, I leave a little more material on the edge so that they have a better chance of surviving, I just have to spend an extra 5 minutes grinding that little excess off which isn't a big deal.

[Joe Chandler]

Originally Posted by Russel Baldridge

While a fast oil is solid advice, heated water is not out of the question. I've only broken one out of ten razors made of 1095 that were quenched in water. And in fact the one that broke, should not have, it was my fault.

But then again, I leave a little more material on the edge so that they have a better chance of surviving, I just have to spend an extra 5 minutes grinding that little excess off which isn't a big deal.

You can't be saying just plain ol' heated water, can you? Brine, I can see, but plain water would allow the creation of a vapor jacket around the blade, slowing down the quench and rendering it ineffective for a steel like 1095 that needs a near immediate quench. I think you have something like 1 second to get it cooled off from quenching temperature or it won't get fully hard.

[Russel Baldridge]

Yes, I mean plain water. For 1095 you have ~1 second to get the blade down under ~900 degrees and much more time than is necessary to get it down to room temp. With my current procedure the exposed portion of the blade stops sizzling in the water within .5 to 1 second, the back of the blade follows at around 4 seconds (clay treatment).

I've yet to have a blade come out of the water any softer than a file, and they break like glass if hit with a hammer (did this on a test piece of 1095 put through my usual forging, normalizing, heat treating cycle, before tempering).

Salts and surfactants are sometimes necessary for lower carbon content steels, but it is not uncommon to use plain water for the higher carbon versions.

[Joe Chandler]

Originally Posted by Russel Baldridge

Yes, I mean plain water. For 1095 you have ~1 second to get the blade down under ~900 degrees and much more time than is necessary to get it down to room temp. With my current procedure the exposed portion of the blade stops sizzling in the water within .5 to 1 second, the back of the blade follows at around 4 seconds (clay treatment).

I've yet to have a blade come out of the water any softer than a file, and they break like glass if hit with a hammer (did this on a test piece of 1095 put through my usual forging, normalizing, heat treating cycle, before tempering).

Salts and surfactants are sometimes necessary for lower carbon content steels, but it is not uncommon to use plain water for the higher carbon versions.

You learn something new every day. If you say it works for you, I certainly can't dispute it.

[jimmyseymour]

some good information here. the only thing i didn't see about choosing a blade steel to make knives with is wether you planned on heat treating the steel yourself or have someone else do it. If you plan on heat treating it yourself and don't have a good oven yet then stay away from stainless. Carbon steel can be heat treated at home with very little money compared to stainless if your not going to go buy salt pots, or ln dewer's. If you want to quench in oil and do it the old fasioned way carbon would be the way to go. Then you have to figure in your wallet and see what's in your budget for steel types realizing that the more exotic alloys cost more, not just in intial cost, but also in belts and other equipment to work it. Even if you don't have a good oven yet you can still work the stainless and send it off to be heat treated by people like paul boss, until you get your own oven.

[Mike Blue]

Originally Posted by Joe Chandler

. but plain water would allow the creation of a vapor jacket around the blade, slowing down the quench and rendering it ineffective for a steel like 1095 that needs a near immediate quench.

It's worthwhile to discuss the vapor jacket problem. It might cause a large piece of steel, say bowie knife sized, to have just enough of a delay that the heat treatment could be uneven (non uniform). But with the conversion of martensite from austenite running at the speed of sound (Verhoeven), when compared with a half to one second, as Russell points out "when it stops sizzling", the vapor jacket phase is very slow. The martensite's already done despite the bubbles. And unlikely to be much of an influence in a razor sized section of steel because there is significantly less mass to cool down across a much thinner section.

Even oils will have vapor jackets from the oil burning and flashing into smoke and they are considered slower quenches than water. Nobody seems to worry about the problem in an oil bath, but it keeps coming up with water because if the timing is right, there could be an influence.