Help me forge a razor

Good evening (or what time of day you are reading this) gentlemen.

I have a question about steeltypes in straight razors.

The first razor I made was patternwelded, made of UHB20C and 15N20. I don't know if you use the same names for the steeltypes, but these are european names. They are bought from https://www.nordellknives.com/portal...56&language=se

The problem was the hardness of the blade. The blade doesn't hold an edge, but it looks nice:o.

I read about you using O1 but as I thought that O1 was very likely to rust, even if you just leave it over night... But I saw it recommended in several posts.

What can you recommend? It would be perfect if I can buy it in Denmark, Germany or Sweden.

Thanks and regards
Kristian :o

See this thread here: http://straightrazorpalace.com/forge...el-blades.html

I've used O-1 & 1095 with great success. Knowing a good heat treater is of great importance. You HAVE to post your results once you get done...
Scott

Thanks :)

And I promise that I will post the results of my efforts. But I've been busy building my smithy/workshop lately (that means the past half year). I promise I will post my work :)

Mange hilsner Kristian

I doubt that I will ever be happy with stainless steel blades. So I will live with "rust" issues. I have not been using straights for very long, but have carried a pocket knife forever. I have never had a rust issue on any EDC knives. I do oil and keep sharp. The last 3 EDC knives have been SS. 2 were 440 and the currant is S30V. they are the only 3 SS knives I have carried and DO NOT hold an edge like my other knives. The S30 V seems to be the best of the 3. There are some other SS out there but I have not used them personally. My kitchen knives are SS and I hate them. Wife likes them though because they are a matched set, so I sharpen often.

D2 is semi stainless but I do not know how it works for razors.

If you polish very highly, then you will have less of an issue with rust.

Jeff

Quote:

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Originally Posted by KristianSestoft

... The first razor I made was patternwelded, made of UHB20C and 15N20. I don't know if you use the same names for the steeltypes, but these are european names. ...

The problem was the hardness of the blade. The blade doesn't hold an edge, but it looks nice:o.

I read about you using O1 but as I thought that O1 was very likely to rust, even if you just leave it over night... But I saw it recommended in several posts. ...

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Hello Kristian,

The steels you are using in the patterned steel are just fine. How was this steel hardened? Temperatures and times would be very helpful as well as the quench medium. If you tried to harden them in oil, you may need to try quenching them in water.

O-1 is a very good steel. It does not rust any more or less than any other carbon steel. It's called 1.2510 100MnCrW4. Any of your suppliers should be able to find it under that number/name.

Hello Mike, and thanks

I ground the blade very narrow, so I did not have too much to grind away afterwards. My grinder at that time was a monster, full speed, only grit 60 belts. I hand rubbed until grit 600 and hardened in a charcoal forge using the magnet method. I held it at the temp for maximum 10 minutes (maybe far too short?). I quenched in lukewarm oil, moving the blade to make it cool down faster.

This leads me to my next question: How should I harden a SR blade? And have you got any hardening diagrams fot O1?

It is possible that ten minutes in a charcoal fire could have burned enough carbon out of the the very thin edge section to make it difficult to harden (decarburization). A charcoal or coal fire can do that. I use liquid propane and have the burner adjusted to make a reducing atmosphere so there is minimal carbon loss.

O-1 should be heated to 1450-1500 F and held for a 10 minutes to allow all the carbon to go into solution. The amount of time that you can afford must be balanced that against the risk of the fire as above but O-1 does not decarb at the same rate as other steels. Non magnetic is a good indicator for folks that do not have sophisticated equipment (not an absolute requirement for doing this). But O-1 also requires that you get from the heat source and into the oil within no more than 10 seconds, but quicker is better. Any delay and you will miss the nose of the cooling curve and it won't harden to it's best potential. The nice thing about steel is that if this doesn't happen the first time, just heat it up and try again.

Kevin sums up O-1 and deserves credit for this succinct discussion. http://www.cashenblades.com/steel/o1.html

Quote:

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Originally Posted by Mike Blue

But O-1 also requires that you get from the heat source and into the oil within no more than 10 seconds, but quicker is better. Any delay and you will miss the nose of the cooling curve and it won't harden to it's best potential.

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It took less that 1.5 seconds from taking the blade out of the furnace until quenching. I got that covered ;)

I think you're right about the decarburization. I think it influences thin blades like SR blades, but a skilled blacksmith told me that "it doesn't matter" (in heavy german accent :D ) when handeling regular knifeblades. More material is usually ground off later on, and the 'decarbed' material will disappear anyway. I got a frequency convertor to mount on my grinder so I can grind the blade very slow, avoiding to heat the blade to more than hand warm. I will never get to tempering temperature and risk ruining the heat treatment by using this method.

-Kristian

A friend of mine says 01 will rust no soon as look at it.
Untrue, anyone who owns a decent razor should know how to look after it.
Also if you get a mirror finish it's quite difficult for moisture to get a purchase.
Alternatively you may quite like the patina with use look that razors can get.

Joe

I think you're on the right track Kristian. Thin blades will decarb faster than a thick blade. It's why so many makers leave a little extra on the sides to grind away later. A good VFD is very valuable.

Joe, that's a good point about the polish. A bright surface will rust less.

Excellent info here from all who posted. Thanks.

Quote:

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Originally Posted by KristianSestoft

I got a frequency convertor to mount on my grinder so I can grind the blade very slow, avoiding to heat the blade to more than hand warm. I will never get to tempering temperature and risk ruining the heat treatment by using this method.

-Kristian

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Don't be too paranoid either.
Temper termperatures are way beyond what you could hold in your hand without blistering.
Thinner surfaces heat up quicker, but on the whole, as long as you can touch the razor with your fingers and not burn then, the steel will be just fine.

Yeah:) I guess you are right about the mirror finish. Now I just have to learn how to make it.

I can get belts up to grit 600 on my new grinder, and by using the frequency converter I'll be able to finish at the grinder at a quite high polish. The rest can be done by hand. But how high should I go on the fine sandpaper / polishing paper? The finest I have easy and cheap access to is grit 1200.

How should I polish a blade? I think I want a mirror / near mirror finish.

I usually finish up to 2000 grit by hand, followed by a buffer and jewelers rouge. I personally feel that the buffer is the most dangerous tool in the shop, over the bandsaw, table saw, or miter saw. Don't let it snatch whatever you are working on out of your hands.

When doing the hand work, I found a piece of radiator hose that was about 1 1/2" in diameter. I cut it to about 6" long & cut a tree limb that would fit in it tightly. I use this to help sanding the hollow by hand. Works great when working with 1/4 sheets of sandpaper.

That's a nice idea, using a limb and a radiator hose.
But isn't the hose much smaller than the wheel of your grinder? My contact wheel is 18 cm in diameter (7.1 inch)... you mentioned the hose to be 1 1/2" in diameter... I would guess that by using a smaller guide for the paper, you are able to make sure where you sand instead of using a paper 'holder' in the same diameter as the concact wheel?

And how hard is the buffer? like this:
http://www.caswellplating.com/buffs/...enim_buffs.jpg
Or like this: http://www.hiwtc.com/photo/products/19/07/23/72374.jpg
Or maybe like this:http://www.caswellplating.com/buffs/...atventbuff.jpg

In very general terms, of the wheels shown, in order, the first black ones have more stitching and will be stiffer = more resistance to pressure against the wheel. This provides for more cutting. These are best used for larger grit compounds to remove larger scratches. The yellow wheels have less stitching = medium to soft, less resistance. With a finer grit these are very good for blending contours. The white wheels have very little stitching and are good for the final grades of polishing to a very fine surface. I'd recommend, as others do, keep one set of wheels for each compound you use. Trying to remove a heavy cutting compound like black from a wheel and then attempting a high polish will leave heartbreaking scratches and more work.

And, because the buffer is the most dangerous tool in the shop, the looser the wheel, the more likely it will catch something and fling it somewhere. Preferably not into soft biological bits. :)

2 things that are done for razors is that the grinding is done in 2 stages, before HT & after HT.
Before HT the grind is left approx 1/16" thick at the edge and 1/8" wider than the desired end result so that any decarb can be ground off. After HT the final shaping and grinding/polishing is performed.
Hope this helps, :D