Thread: Two questions from a newbie

I have been making knives for a few years now and recently got the itch to try my hand at straight razors. It seems like they are a completely different animal, but after some reading and research I think I’m ready for the challenge.

Two questions that I can’t figure out-

How thin do you want the edge to get during finish grinding before moving to the hone? For most knives I’ve done it’s been around 5-10 thousandths before sharpening. Is that too think for a razor?

I only do stock removal right now, and typically do all grinding after heat treat to avoid warps during quench. Is that normally how it’s done for razors or should I be hogging off some material before hardening?

Should have it ready to finish grind, why do all that hogging out on a hardened blade? And a razors edge is much thinner than a knife so it doesn’t translate. You only want to leave enough edge to keep it from warp at heat treat

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Is this you?


https://www.instagram.com/p/5pELL7ia1i/?hl=en
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Nice looking knife
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https://www.razorsharpunlimited.com/...ions/benchmade

Leave yourself like .06”at the edge. I grind everything else pretty close. I leave like an extra .015” around the whole blade before heat treat. Post heat treat I like to take the edge down to about .005” and set the bevels. Make sure to apex the edge. This will show you where your grinding isn’t consistent. You can finish grinding down to almost no bevel, you’re looking for something thin like .03” or less. Another technique one of the members here showed me was to grind the edge down to where it starts to foil, then cut your bevel. I have only tried that a couple of times but have yet to get the feel for it.

OK, a few guidelines ....

Use unalloyed high carbon steel. 1075 - 1095.
It gives a finer grain size resulting in a smoother shaving edge.
No to 440C except as a practice razor.

Ratios .... blade width to spine thickness 4:1 or less
Ignore this and the bevel gets very wide, difficult to hone, and the edge is prone to chipping.
Leave a small amount of extra width to compensate for a decarburized edge that will need to be ground off after heat treatment.
Then you will know you have good steel on the edge.

Rough hollow grind to an edge thickness of about a dime.
Bring the decorative spine work, spine and tang to a high finish before heat treating/tempering. Make for less work afterwards.

Finish grind slowly. The enemy is heat and losing the temper.
Take the edge as thin as you can then hone. The honing will show you where the bevel is uneven and wide in spots. This will tell you where to grind some more. Repeat this last process as necessary..


Just my 2¢

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...jfk742 has made some very nice razors, listen to him ......

Grinding to a foil edge relies a lot on the sound of the belt. I don't even try.

You can get very close to a foil when you send out the blade. This I can do.

Originally Posted by randydance062449

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Is this you?


https://www.instagram.com/p/5pELL7ia1i/?hl=en
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Nice looking knife
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https://www.razorsharpunlimited.com/...ions/benchmade

No that’s not one of mine. But I guess I need to look him up to see if we are related.

Thanks to everyone for the tips. I’ve got a bar of .250 1084 on hand right now so I’ll get busy practicing on that. I’m sure I’ll have a few more questions once I get going.

What you are asking is beyond me so i cant comment. But we do have some great razor makers on this forum that have been doing it for many years. Just be sure to do it right and come out with the proper geometry and grind.

Originally Posted by randydance062449

OK, a few guidelines ....Just my 2¢

Gee Randy you've learned a lot more than i have about razors since I first met you. LOL. That's worth way more than 2p.

One knifemaker to another...listen to these guys and this gets a lot easier.

As to my advice, learn to thermal cycle that bar of 1084 and eliminate the warping tendencies before you begin. You can do that with a very simple heat treatment setup even if you don't forge any blades.