Drilling hardened steel

[Timberwolf]

Good tip. I've been trying to drill holes in hardened knife tangs for pins with TiN coated bits without success. I'll have to give this a try.

,,,,,,,,,,,,,,,,
You may know this but you can sharpen a masonry bit several times when it gets dull, on a bench grinder using a green {silicon carbide} wheel...silicon carbide is harder than tungsten carbide. When the cutting edge gets blunted, just touch it up, carefully following the same angles used by the manufacturer. Green wheels are cheap....You may be surprised that the bits {when sharpened correctly} will probably be sharper than when new....You can also "narrow" the web of the bit using a diamond burr...A narrower web will reduce the tendency of the bit to 'skate' on a polished, hard surface.

As to the TiN coated bits, I have found that some of those bits are just plated, which does little for the cheaper steel they are made from IMO.....For a really good bit, look for the ones that contain high percentages of cobalt...I use lathe bits who's HSS contains 8% cobalt and they compete favorably with tungsten carbide IMO. They take the heat like a champ..
..I used to have occasion to drill out broken grade 8 bolts and used high cobalt bits from Lawton Products...don't know if they are still in business tho..but they drilled that tough steel like it was butter.