Some steels feel "stickier" more grabby when grinding

ashwinearl

ashwinearl

Knifemaker / Craftsman / Service Provider
Joined
Nov 9, 2006
Messages
562
Hi All,

I am experimenting with different steels: O1 - ebay, 15N20 (Alpha), 80CRV2 (Alpha), 1084 (Alpha), 8670 (Alpha)

The 15N20 and 80CRV have ground nicer in their original state compared to the other steels. I did have issues drilling into the 15N20 so maybe it is overall harder to begin with.

O1, 1084, 8670 have felt very grabby on the belts and difficult to control even with new belts. I am experiencing this flat grinding (un-hardend A2 ground platen from Oregon Knife) and hollow grinding 10" wheel. Belts have included VSM 885 50g and 100g ceramic, Hermes 346 AO 100 and 200. I have a grinder in a box with 1HP motor with VFD and tried experimenting with speeds.

I sent the O1 out to JT heat treatment. And after HT, it ground very nice. I have read that about O1. The 15n20 and 80CRV2 I did myself in my baby forge and they too grind nice after ht. I m going to do the 1084 and 8670 soon myself and compare.

I am wondering if others experience different levels of control/stickiness with certain steels/belts pre and post ht. I am thinking that I might do better just performing rough grinding when soft and save the rest for after heat treat.

Thanks
 
I use the same steels, I use the same belts, I even have the same grinder.

I have not experienced it feeling grabby.

What I do know is brand new belts cut like lazers and at anytime it seems like the grind is having any trouble it usually time for a fresh belt
 
are you sure its grabbing the belt and not the tool rest ? i also have never noticed grabbiness.
 
Some steels do feel more gummy when grinding pre heat treat. That's why I do 90 percent of my grinding post heat treat now.
 
john april said:
are you sure its grabbing the belt and not the tool rest ? i also have never noticed grabbiness.
Click to expand...

This is without the tool rest. I think much of it has to do with experience level and tentativeness with pressure control. My strong side isn't as bad and know that I hold the blade firmer and with more confidence compared to my weak side.
 
Matt R said:
Some steels do feel more gummy when grinding pre heat treat. That's why I do 90 percent of my grinding post heat treat now.
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I also prefer doing 95% plus of my work post HT. I get a crisp grind rather than a smear.. I use all Stainless Steels, 440C can be a tad gummy to grind even after HT.. Fresh belts are always best!————-I also use VSM Ceramic Belts , I only use about 50-60% of the grit while grinding HTed blades then they go into the pile for profiling or I give them to a young noob that’s broke & just starting out. The belts create too much heat & don’t give a crisp grind anymore..
 
The first time that I ground 3v, it was annealed and I notice that it seemed built up heat faster than simple steels. That didn't seem to be as much of a problem when I ground it in its hardened state. Weird.
 
The 15n20 comes a lot harder than the O1. Anywhere from 40 to 46 rc. Makes sense that it may feel a bit different than something around 15 or 20 rc.
 
Rhinoknives1 said:
I also prefer doing 95% plus of my work post HT. I get a crisp grind rather than a smear.. I use all Stainless Steels, 440C can be a tad gummy to grind even after HT.. Fresh belts are always best!————-I also use VSM Ceramic Belts , I only use about 50-60% of the grit while grinding HTed blades then they go into the pile for profiling or I give them to a young noob that’s broke & just starting out. The belts create too much heat & don’t give a crisp grind anymore..
Click to expand...

I was going to post about crisp belts. I must have 50 belts that I can't do much but profile with.
They do work well on tapering using my 14 inch wheel. Still, I have so many my rack wants to fall over.
You give me some confirmation that I need to just figure out how to get them out of my garage.
 
Brock Cutlery said:
I was going to post about crisp belts. I must have 50 belts that I can't do much but profile with.
They do work well on tapering using my 14 inch wheel. Still, I have so many my rack wants to fall over.
You give me some confirmation that I need to just figure out how to get them out of my garage.
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I’m sure there is noob in the area that would love to have those belts. Are you sharing your knowledge with any now? ————/-//———————//////—Speaking of which! I’m due for another noob to share with. Any in the Westside of Los Angeles , Santa Monica Area? I’ll be glad to share with you how I mangle Steel & expensive Hardwoods!:D
 
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Just to follow up. I heat treated my 1084 and 8670 and it did grind much nicer for me. Slower, naturally, but more controlled for the most part. This echoed my experience with O1.

Now, I need to determine the trade offs in terms of how much to grind before heat treat at a faster pace, vs how much after heat treat at slower pace with some of these steels. Of course, if I keep blowing through edges and over grinding at the spine with soft steels then the decision gets easier.

I am not heavy handed and haven't built up that finger toughness so dunk every pass anyway.

Thanks
 
ashwinearl said:
Just to follow up. I heat treated my 1084 and 8670 and it did grind much nicer for me. Slower, naturally, but more controlled for the most part. This echoed my experience with O1.

Now, I need to determine the trade offs in terms of how much to grind before heat treat at a faster pace, vs how much after heat treat at slower pace with some of these steels. Of course, if I keep blowing through edges and over grinding at the spine with soft steels then the decision gets easier.

I am not heavy handed and haven't built up that finger toughness so dunk every pass anyway.

Thanks
Click to expand...
nothing wrong with dunking every pass! I do and this is what I invented my Rhino Finger Skins for... now you can buy cheap leather gloves and tape them with white Athletic tape, to your fingers that’s what I did before the Skins. I don’t have that burned spot in the middle of my thumbs etc anymore!!
 
I use these rubber tips from the office supply store right now. They work ok and still provide some tactile feel. Their problem, which your finger skins solve, is that they don't extend far enough on the index finger to protect between the first and second knuckle which I use to support the spine.

I tried a push stick but had no control. I might try again. And need to try your skins out.

mL9e4rr.jpg
 
Rhinoknives1 said:
I’m sure there is noob in the area that would love to have those belts. Are you sharing your knowledge with any now? ————/-//———————//////—Speaking of which! I’m due for another noob to share with. Any in the Westside of Los Angeles , Santa Monica Area? I’ll be glad to share with you how I mangle Steel & expensive Hardwoods!:D
Click to expand...

I'm happy to share knowledge and give some belts, but not aware of any other less experienced knife makers around these parts.
I do get down to Phoenix though, if there is anyone that this might help?
 
Sometimes your platen can get magnetic and affect your control of the blade during passes. Some steels have a greater tendency to become magnetic than others.

Additionally, the softer the steel, the more "gummy" it is. Gumminess can cause the blade to sink into the belt a bit and mess up grinds. Harder and more wear resistant steel "skates" across the belt.
 
ashwinearl said:
I use these rubber tips from the office supply store right now. They work ok and still provide some tactile feel. Their problem, which your finger skins solve, is that they don't extend far enough on the index finger to protect between the first and second knuckle which I use to support the spine.

I tried a push stick but had no control. I might try again. And need to try your skins out.

mL9e4rr.jpg
Click to expand...
That was my findings when researching to make my Skins. The two fingers that take most of the beating & heat are our index finger & thumb. ———————-Rhino skins are primarily for thermal protection but the do help quite a bit if you make direct contact with the belt from grinding off the fleshy parts! ——— Buy some cheap leather gardening gloves and cut the finger & thumb off past the second & first knuckle and tape them off with white Tape or even 1” blue painters tape...
 
A few things I thought I would bring up is decarb and wear resistance. When I do happen to get decarb (usually when I omit the anti-scaling compound), it definitely feels 'gummy' on the grinder. Once you hit the hardened steel, it starts to feel different. Wear resistance has a major role in grinding as well, especially after heat treat. I can tell a huge difference between say 1080 and CruForgeV or D2. The highly wear resistant steels will feel slippery/glassy compared to gummy and coincidentally will wear down your belts faster.

I actually decided against using CruForgeV as my main steel choice because the high wear resistance has the hidden cost of buying more belts. It will even wear down your nice Cubitron II 984s like they are AO belts.
 
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