Drill Bits for Very Hard Bricks and Mortar?

[Foresty Forest]

I need a set of drill bits for my house which has very hard bricks and mortar. Somebody told me what to buy, but I just can't remember the name of them? My existing masonry bits aren't doing it, even with my SDS drill.

Thanks...

 

[Deleted member 174758]

Hilti, Heller Trijet, etc. You probably don't need a set as such when you consider that many of the fixings you are dealing with are brown plugs (7mm) or red plugs (5.5mm). I still have the remains of sets bought 25 to 30 years ago with oddball unused sizes.

 

[^woody^]

The cheap ones from toolstation have drilled all the hardest blues, reds, blocks, concrete I've come across for years. Is the drill working properly?

 

[Foresty Forest]

The cheap ones from toolstation have drilled all the hardest blues, reds, blocks, concrete I've come across for years. Is the drill working properly?

They are working, it's just a bit laborious. I've turned the hammer off, as someone said it can cause the bricks to fracture.

 

[Burnerman]

No way you'll drill masonry without hammer action....if you're worried about splitting the bricks, drill slowly and reduce pressure - but I doubt if they'll split anyway.
John

 

[^woody^]

Use the hammer, but try not pressing really hard and let the bit bounce a little more - you'll feel it, and cycle this between pressing hard and less so.

 

[Deleted member 174758]

You shouldn't need much pressure on an SDS drill just enough to keep it running straight

 

[opps]

They are working, it's just a bit laborious. I've turned the hammer off, as someone said it can cause the bricks to fracture.

Are you sure it is a SDS drill? Most of them don't let you turn off the hammer action (my Metabo does but my Bosch doesn't). Sorry, I am not intentionally being condescending. As Woody said, even a cheap SDS bit should be able to deal with hard bricks.

Last year when drilling through a concrete lintel I hit a rebar and it shattered the head on my 7mm SDS bit. I purchased some Makita Nemesis bits and they drilled through the rebar without issue.

 

[Deleted member 174758]

Are you sure it is a SDS drill? Most of them don't let you turn off the hammer action (my Metabo does but my Bosch doesn't).

I think you'll find that the vast majority of SDS drills on the market these days, and for quite a few years now, have featured hammer stop (rotation only mode). This allows you to use an SDS to drill timber using a conversion chuck and auger bits - rather handy for lock mortising. My original blue Bosch bought in the early 1980s had that feature, although it didn't have rotation stop

With you on the quality drill bits, though. I've had problems in the past drilling through rebar-infested concrete where only 3- or 4-"lobe" drills could manage. Have to admit that Hilti were the best, but oh, what a price! (16mm diameter x 450mm cost us £65 a pop - plus VAT)

Whoever advises that a user turn off the hammer action for masonry drilling with an SDS fundamentally misunderstands how these drills work. The bits are far from sharp to start with (the points are sharpened for strength, not cutting performance in soft materials) - they work by percussive action and the rotation is mainly to remove the waste produced by the chiselling action of hammering. Turn hammer action off and the drill bit becomes a rather ineffectual rotary scraper that can barely drill into many hard materials and which will round over and overheat in next to no time. I work on enough Victorian buildings to know that "colliery bricks" can be brittle and shatter from time to time, but most of the time you can find at least one decent brick to drill into- not necessarilly where you want it, though

 

[opps]

I think you'll find that the vast majority of SDS drills on the market these days, and for quite a few years now, have featured hammer stop (rotation only mode).

Point taken. Now I think back, even my cheapo 6KG drill had a rotation only mode.

With you on the quality drill bits, though. I've had problems in the past drilling through rebar-infested concrete where only 3- or 4-"lobe" drills could manage. Have to admit that Hilti were the best, but oh, what a price! (16mm diameter x 450mm cost us £65 a pop - plus VAT)

I have never quite understood why their accessories are so expensive. I have never used their bits.

Whoever advises that a user turn off the hammer action for masonry drilling with an SDS fundamentally misunderstands how these drills work.

It was that which made me think that the OP might not be using a SDS. BTW, I too want to write "an SDS" rather "a SDS", dunno why though.