Tough masonry drill bits

[thewinelake]

I'm trying to drill a 6mm hole in some remarkably hard limestone.
It seems that normal carbide tipped masonry bits will drill perhaps 5mm or so before getting noticeably blunt and slow. Given that these only cost about £2 each, I can live with that, but just wondering what the "Rolls Royce" of masonry drill bits might be?

I've also tried a diamond-encrusted hole saw thing, but that didn't really work well for me.

I don't have an SDS drill, but suspect that the "Pro" nature of such things might make them a good option. Although for a 6mm hole it does seem overkill!

What kind of rotational speed would the panel recommend for this kind of application?

Thanks!

 

[Deleted member 174758]

SDS is the way to go and is the way the pros drill most things these days. I have had success with Bosch blue Construct multi materials drills in a cordless drill into Accrington brick - however my cordless combination is a Makita DHP481 which can easily outperform a lot of corded drills, so no surprises there

 

[thewinelake]

Cheers. Would one use it in a hammer mode, or would that risk cracking the tile?

 

[Deleted member 174758]

Rotary mode only to get through the tile as hammer action will Defford risk cracking a tile, then hammer mode once you are through the tile

 

[Chud]

Is this a limestone tile you're drilling?

If so then the diamond holesaw should have worked but they are 'non-hammer' and many need to be used wet.

 

[Kersley]

Whatever you do don't use a hammer drill because you will crack your tiles.
What you need is a proper pointed tile drill bit or even better a diamond holesaw bit. slow speed is a must with frequent spray of water to keep the bit cool.
your standard cordless drill is more than enough.

https://www.amazon.co.uk/SODIAL-Gla...dp/B008S7ZDYK?ie=UTF8&*Version*=1&*entries*=0


https://www.amazon.co.uk/ZJchao-Dia...UTF8&qid=1461417920&sr=1-11&keywords=tile+bit