I'm upgrading my grinder to CBN wheels and it's my understanding that using anything other than hardened or hss will ruin these wheels. If in doubt what's the best way to determine if the steel is actually hardened or hss. Thanks
Dave
Dave
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Stupid question #1
- Thread starter Dave DeJong
- Start date
Try running the corner of a file lightly on the shank. It will slide easily on hardened steel and probably dig in on soft material.
Dave, my father always said the only stupid question is the one not asked. What will ruin or clog up CBN wheels? Curious, too.
john lucas
AAW Forum Expert
High speed steel or particle metal steels are OK. High carbon steel can clog it. Generally HSS tools.will.ha e HSS stamped on them. Thompson, Dway and Carter tools can be sharpe ed on them but aren't stamped as HSS they are M42 or particle.metal.
If you do sharpen a high carbon steel.tool you havent ruined it. Sharpening other has tools.will.unclog it unless you really clogged it by sharpening a lot of tools.
If you do sharpen a high carbon steel.tool you havent ruined it. Sharpening other has tools.will.unclog it unless you really clogged it by sharpening a lot of tools.
Thanks for the replies. I'm probably being just a little bit too cautious.
Thanks, John.
Check with Woodturners Wonders its a good place to talk to someone who will answer your questions.
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I believe that CBN could be used to sharpen tool steels like O1 and W1 if it has been tempered, but I would be hesitant to use it if the tool steel is in the annealed state. i wouldn't use CBN to grind mild steel. Tool steel that isn't HSS is usually sold in the annealed state.
after all this . if the wheel is clog How do you unclog it ?
Well, I have this insatiable need to experiment..... Generally you want to sharpen nothing but 'hardened' steels on your CBN wheels. So just about all of our turning tools, shovel blades, axes, bench chisels, and probably a few others will do fine. I had an old set that didn't cut well any more after many years, and I also tried to touch up some carbide on them. It did take the carbide down, but that really dulled the wheels. So, just to see what would happen, I ground some aluminum, brass, copper, and cold rolled steel on the wheel, which left very visible colored rings around the wheel. They were gone in about a month. You can feel softer metal building up on the wheel. There is a noticeable ticking sound when it starts to load up. Best way to get it off is to take a scraper to the wheel to sharpen it. It may take a couple of times to get it off, but the scraper kind of peels off the built up metal. I also regularly put some lapping fluid on the bevel of my tools before sharpening (this is in my platform sharpening video). This also helps loosen up metal build up and the sludge that comes from sharpening tools with wet wood on them. Dave Schweitzer of D Way (now owned by Jimmy Allen of Boxmaster Tools) said that it doesn't hurt to take your wheels if they are looking black from all of the accumulated gunk, soak them in water with detergent for a few hours and then use a bristle brush to clean them off. It gets the deep down in stuff off of the wheel. I always sharpen my Big Ugly tools on my grinder. They are tantung (almost as hard as carbide but easy to sharpen on standard grinder wheels) which is silver soldered onto bar stock, which is one of the soft metals you should not grind on the CBN wheels. Little to no problem with build up since the tantung peels off any metal that builds up. I do grind off most of the bevel on the bar stock on a belt sander, and keep it pretty much that way.
So, you may be able to ruin a CBN wheel by really loading it up with soft metal, but it would be really noticeable. If you get a little loading, you can clean it up simply by sharpening a scraper a couple of times. I would not make a habit of sharpening softer metals on the wheels though.
Oh, I did retire that one set that I ground the carbide on. I did grind off the points on some galvanized screws, which left black streaks on the wheel, but didn't seem to bother the cutting action...
robo hippy
So, you may be able to ruin a CBN wheel by really loading it up with soft metal, but it would be really noticeable. If you get a little loading, you can clean it up simply by sharpening a scraper a couple of times. I would not make a habit of sharpening softer metals on the wheels though.
Oh, I did retire that one set that I ground the carbide on. I did grind off the points on some galvanized screws, which left black streaks on the wheel, but didn't seem to bother the cutting action...
robo hippy
john lucas
AAW Forum Expert
I ground a Hunter carbide cutter until 50% of it was gone so I could photograph it and measure the cutting angle. I did it on my 180 Dway CBN wheel. Didn't seem to hurt it. 9
The carbide I ground on my wheels was an attempt at getting more life out of an ancient set of McNaughton coring blades and I had a saw shop braze some carbide tips on them. Much coarser than the newer micro/nano grained carbides available now.
robo hippy
robo hippy