Thread: Sharpening tungsten carbide masonry bits

Yes, aluminium oxide it too soft, it will have little effect on the tungsten carbide and the wheel will disappear before your eyes

A $10 lapidary diamond disc on the side of a grinding wheel will do a great job on TC and can be left permanently on the side of the wheel.

My setup uses a disc so that it leaves the edges of the wheel free..
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Thanks BobL. What grit would you recommend?

Originally Posted by Lappa

Thanks BobL. What grit would you recommend?

Same as you would use on a green wheel.
I use an 80 grit but it you wanted to get fancy you might go for say a 60 and then a 180.

I use this mob. https://www.thk.hk/online-cart.php?cid=36&sid=39

Diamond wheels take off a lot quickly and TC only needs a touch. I use a 400 wheel on my Tormek with a 400 flat disc on the side.

CBN is also an option.

Although you can use CBN for tungsten it is not considered suitable

Originally Posted by China

Although you can use CBN for tungsten it is not considered suitable

It can also stuff your CBN wheel

Why do you want to sharpen your masonry bits?? Masonry bits don't have a sharp edge per se. The tungsten tip is there for wear resistance, not so much as a cutting edge. Masonry drill tip (sharp) edges will become rounded over quite quickly but this has very little effect on its cutting ability. When drilling masonry, the tungsten tip is there to apply the impact of the impact drill, it is this impact that does most of the cutting, the width of the tip maintains the hole diameter, the remainder of the drill bit (flutes) is there to remove the masonry "dust". I'm sure you have noticed that the masonry drill body is narrower than the tungsten tip.

When I talk about sharpening a masonry bit I don't mean like a drill bit to drill metal or wood but just so as to restore really rounded over tips back to original.
It's definitely easier when the edge is not completely rounded over.
A more pointed versus completely rounded tip also helps reduce a wandering start.
I do sharpen some masonry bits with a much sharper edged than is needed for masonry and that is when use them in a Drill press to drill through hardened chainsaw bars.

I have sharpened TC masonry drills to drill thru hardened steel, or old angle iron that was made for the railways and has a lot of rubbish in its mix and instantly destroys normal drills.

I needed to enlarge the 3/8" hole in ceramic electric fence insulators to accept 10mm when the bolt retailers stopped carrying imperial gal bolts and once again sharpening a TC drill got me out of trouble.

I just used the normal gray wheel that was on the grinder, slow and I used the grinding to reface my wheel.