Grinding for hours...

How long does it take you to grind a typical 4 inch blade?


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I've done quite a bit with the Bohler N690 pre and post HT grinding. It's pretty easy on belts falls in line with CPM 154 and some 440C. I think it finishes better than 440C.
 
With CPM 154 I don't grind post heat treat. I go from 36 grit, 60 grit, 120 grit, 220 grit, 400 grit, 220 norax. Then hand sand at 400 grit. Send off to Pau Bos heat treating. When I get the blades back I hand sand with 400 grit up to 1200 grit. It goes fast.
I would say a 4" drop point blade would take less than ten minutes to put the primary bevels in with a ceramic 36 grit belt. Maybe more like five minutes.

Now, many years ago David Boyle used to advertise some kind of cobalt blade. I remember there were advertisements of him using a blade of that material to cut 1" hemp rope. He had a whole pickup truck full of cut pieces and was still cutting. A customer got one of those blanks for me to grind a knife out of. It was 1/8" thick. I couldn't believe how long it took to grind the bevels. Sharp belts just didn't want to cut it. I wouldn't have believed it if I hadn't tried it. That was the one and only blade I ever made out of that material. Sounds like you are using a similar steel.

Are you using a round contact wheel or the flat platen? A round wheel will cut faster.
 
With CPM 154 I don't grind post heat treat. I go from 36 grit, 60 grit, 120 grit, 220 grit, 400 grit, 220 norax. Then hand sand at 400 grit. Send off to Pau Bos heat treating. When I get the blades back I hand sand with 400 grit up to 1200 grit. It goes fast.
I would say a 4" drop point blade would take less than ten minutes to put the primary bevels in with a ceramic 36 grit belt. Maybe more like five minutes.

Now, many years ago David Boyle used to advertise some kind of cobalt blade. I remember there were advertisements of him using a blade of that material to cut 1" hemp rope. He had a whole pickup truck full of cut pieces and was still cutting. A customer got one of those blanks for me to grind a knife out of. It was 1/8" thick. I couldn't believe how long it took to grind the bevels. Sharp belts just didn't want to cut it. I wouldn't have believed it if I hadn't tried it. That was the one and only blade I ever made out of that material. Sounds like you are using a similar steel.

Are you using a round contact wheel or the flat platen? A round wheel will cut faster.

Thanks for your response!

For my FFG (as in this case) I use a flat platen (made out of 15mm AS-quenched O1). I profile my blanks with a contact wheel, to save the flat platen and for a more efficient material removal. Actually I was getting suspicious of the Niolox already at the profiling stage, it was noticeably harder to cut.
 
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How many times do you stop and look at the progress as you're grinding? That may be a lot of your time, fixing things that would have otherwise fixed themselves.
 
With CPM 154 I don't grind post heat treat. I go from 36 grit, 60 grit, 120 grit, 220 grit, 400 grit, 220 norax. Then hand sand at 400 grit. Send off to Pau Bos heat treating. When I get the blades back I hand sand with 400 grit up to 1200 grit. It goes fast.
I would say a 4" drop point blade would take less than ten minutes to put the primary bevels in with a ceramic 36 grit belt. Maybe more like five minutes.

Now, many years ago David Boyle used to advertise some kind of cobalt blade. I remember there were advertisements of him using a blade of that material to cut 1" hemp rope. He had a whole pickup truck full of cut pieces and was still cutting. A customer got one of those blanks for me to grind a knife out of. It was 1/8" thick. I couldn't believe how long it took to grind the bevels. Sharp belts just didn't want to cut it. I wouldn't have believed it if I hadn't tried it. That was the one and only blade I ever made out of that material. Sounds like you are using a similar steel.

Are you using a round contact wheel or the flat platen? A round wheel will cut faster.
That must be Talonite or Stellite . . . :) They say that if tool steel stays sharp for 6 - 8 hours then Talonite ® will retain an edge for 12 - 14 days :eek:
 
Join the AEB-L bandwagon.Ya won't look back. I run it at 62 for kitchen knives and small slicer edcs. They cut and cut and cut and well ya know.... I run it at 63 for my leather working knives and holy cow......
 
How many times do you stop and look at the progress as you're grinding? That may be a lot of your time, fixing things that would have otherwise fixed themselves.

Not as many times now, as when I was just starting out. I'm pretty familiar with O1, so grinding it doesn't take a lot of checking. But I bet I checked my progress at least twice as often when grinding the Niolox. Since I couldn't believe my eyes how little progress, leaning into a 36 grit belt on my 3 hp grinder, I made.
 
Join the AEB-L bandwagon.Ya won't look back. I run it at 62 for kitchen knives and small slicer edcs. They cut and cut and cut and well ya know.... I run it at 63 for my leather working knives and holy cow......

This sounds like good advice. I've a read lot of good reviews of it. Unfortunately I haven't found a good supplier here in Sweden or Europe. Which is ironic since Uddeholm is a Swedish manufacturer. o_O

But I can get 14C28N, which according to the link below is rather similar. With added Nitrogen.

https://www.alphaknifesupply.com/zdata-bladesteelS-AEBL.htm

https://www.alphaknifesupply.com/zdata-bladesteelS-14C28N.htm
 
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I only use Niolox steel and she's not the most easy steel to work with but makes a good knife.
Stays sharp a long time and doesn't rust even when neglected in a moist kitchen.
Sharpening goes well with DMT diamont sharpeners, never tried natural stones
Just don't try and abrade post HT she'll be a b!tch and won't work with you.

I had a blade finished to 2500 and got some minute scratches during HT. I had to use a 400 EMD stone to get a decent finish again and change the design to a 400 grit finish.

I outsource HT for 8euro/blade inc deep cooling
 
Since I learnt the hard way that Niolox should be nearly finished before heat treat and I didn't want to toss my Moby Dick. Instead, I did a quick finish on it and will give it away to a friend as a utility knife.

Some blades just doesn't want to give up without a fight. Surely I managed to give it a scuff during WEPS sharpening also. Hahaha. I guess I'm allergic to Niolox and should keep away.:confused:

I ordered a couple of bars of 14C28N, can't wait to try it out.

http://smt.sandvik.com/en/products/...14c28n-piece-hardening-deep-freezing-70c-95f/

rQxwNhQ.jpg


3SLIv3d.jpg
 
Since I learnt the hard way that Niolox should be nearly finished before heat treat and I didn't want to toss my Moby Dick. Instead, I did a quick finish on it and will give it away to a friend as a utility knife.

Some blades just doesn't want to give up without a fight. Surely I managed to give it a scuff during WEPS sharpening also. Hahaha. I guess I'm allergic to Niolox and should keep away.:confused:

I ordered a couple of bars of 14C28N, can't wait to try it out.

http://smt.sandvik.com/en/products/...14c28n-piece-hardening-deep-freezing-70c-95f/

rQxwNhQ.jpg


3SLIv3d.jpg
 
Your grinding looks great even with the effort you had to put into it! Frank

Thank you very much. I appreciate it.

This reminds me of when I just started out making knives. I wanted to try a nice steel bolster and (of course) choose 304. Damn, I had a pretty flimsy grinder back then and my Sisyphus incarnated bolster had no intent of giving me an easy victory. Haha, I ground that gummy stuff forever. That stuff is weird to both drill and grind.
 
@currenthill

i dont want to highjack the threat but i cant figure out to do a private message. i saw your grinders in the posted pic. can you tell me the model /maker ? or are they home build ? they do look really down to earth functional and i would love trying to get my grubby mitts on them.
 
@currenthill

i dont want to highjack the threat but i cant figure out to do a private message. i saw your grinders in the posted pic. can you tell me the model /maker ? or are they home build ? they do look really down to earth functional and i would love trying to get my grubby mitts on them.

They are built by a guy in Greece, Nick Argy. They're pretty popular in Europe. He does a good job of making grinders with a nice price/performance. They're not so refined, but very sturdy and will probably last a lifetime. He also makes contact wheels for it.

https://www.youtube.com/channel/UCfbZhrxlxmcwTBQZ3IHe4FQ
 
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