.

what are they made from (main drill body) ? … Non-descript steel [approximating Cheese]

can they be ground for steel? … Geometry, Yes … Durable edge, No

The tip is tungsten carbide and can be ground to a sort of point for steel I understand. I think some sort of 4 facet grind would work. I can't remember where I saw this but could be useful if you have something too hard for a normal drill.

The body of the drill varies according to quality, the better ones are made from a tough steel and the cheap ones from cream cheese. I have used this dodge on more than one occasion, usually involving a steel of unknown origin that has work hardened to the point that HSS won't touch it. I can sharpen drills by hand ( after a fashion ) and the technique I use for sharpening is to present the masonry drill in exactly the same way I would with an ordinary drill. I should point out that I have only used these drills for opening out holes already drilled. Also the carbide tips are very small and prone to breaking. I only really use this as a last resort.

Regards.

David.

You can buy masonry bit that have a ground edge to drill a variety of materials including steel see **LINK**

To quote "High performance bits with multiple diamond-ground carbide tips.
Suitable for masonry, wood, aluminium, structural steel, plastic, concrete B35 and multi-layer materials such as tile on concrete."

I've used them to drill though aluminium then into brick also wood into brick/concrete block.

Bob

Edited By Bob Brown 1 on 02/06/2015 22:29:37

Couple of pics of some commercial TCT twistdrills I have to give you an idea of how to grind, tips are brazed like most masonary drills so will stay put. Looks to hace a 4 facet type grind with a very shallow angle to the first edge .

Edited By JasonB on 03/06/2015 10:05:46

I've had some success with spear point tile drills if this helps.

The other option is to try something like the Bosch Multi-construction drill bits but these aren't as sharp from my experience.

In both cases high drilling pressures are needed.

Jon

.

LOL

Ground quite a few up to get John out of trouble.

Diamond wheel and grind 4 facet, they work fine but don't expect H7 tolerance.

Try to use a decent drill, anything that has a chrome shank is suspect.