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I need to sink 8" TITEN HD concrete anchors into a foundation and through 3" of wood sill plate above the concrete. It would be nice to use one drill bit, but from my research it looks like SDS Plus hammer bits that handle concrete are not spec'ed for wood.

My drill can switch between rotary and hammer, so can switch modes after getting through the wood...but would be nice to not switch bits.

What kind of bit will do both?

I found some multi-material bits but they aren't long enough...

I also found an Carbide-tipped SDS Plus Concrete Rebar Bit. Maybe the carbide bit will do?

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    I think you'll be happier in the long run using a wood bit (auger) and then a concrete bit.
    – RetiredATC
    Sep 7, 2022 at 2:36
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    Why would it be "nice" to use the same drill bit? You do get "universal" bits - but like @Ruskes already answered, forget nice with concrete. Do the job properly. I'd use two drills with the correct bits already set up. I have an HSS drill for wood and an SDS+ for concrete/masonry. Even a power driver would do the wood if you don't have a spare drill but have a sh*tonne of holes to do. Or just do the wood, then do the concrete.
    – Rab
    Sep 7, 2022 at 9:32
  • Bosch Multiconstruction are carbide tipped like masonry drills but the carbide tip is sharpened like metal drill. They work on wood and metal very well, at least when new. No idea about Rebar Demon, those tips look more like "capable of destroying metal" rather than "cuts through wood neatly".
    – Agent_L
    Sep 7, 2022 at 14:40

5 Answers 5

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It would be faster and easier if you use right drill for the material.

Forget nice, just use drill for wood and then switch to drill for concrete.

To prevent damaging wood drill when it hits concrete, set a depth stop.

The hole size for the anchor to work has to be precise (not to big and not to small) specially in the concrete part.

Thus when drilling true concrete do not push it.

When drilling a hole for a concrete fastener, the quality of the hole is critical. For this reason, it is imperative to use a proper drill bit. A proper bit for drilling a hole for a concrete anchor is an ANSI tolerance, carbide-tipped drill bit. The type of carbide-tipped bit needed is dependent upon the type of hammer drill being used. Carbide-tipped drill bits are simply named for their bit retention system (how the bit is held in the drill).

The more teeth the drill has the finer and more precise will the hole be.

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A reasonably sharp masonry bit will drill (poorly) thorough wood. A dullish one will drill quite poorly through wood. But it will make a hole (it just won't be pretty.)

So, you can use one bit, and after a few holes in the concrete ding up the bit, the quality of the holes in the wood will degrade.

Chucking a wood bit into a non-SDS drill would be the nicer, neater hole in the wood solution that does not require changing bits on the SDS, just swapping drills to some nice boring non-hammer drill. Set a depth stop so the wood bit never contacts the concrete.

If you only own the one drill can won't buy another (great place for a Horrible Fright cheapie) drill every wood hole in one operation with a wood bit in the SDS, then swap bits (exactly once) and finish drilling all the holes into the concrete.

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If you only have one drill, then I would mark and drill the holes through the wood first with a wood bit, using a depth stop to just miss the concrete surface.

The change to bit and do the concrete using a masonry bit, again with a suitable depth stop.

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In terms of the tip, it's not the carbide hardness that matters for the wood, but whether the tip cuts: masonry and concrete bits do not cut, they hammer and grind.

Such a bit set to wood will just rub, grind and wear heated wood fibres. It works, but it's not efficient.

My concern with this is the unnecessary heating of the bit when applied to wood, which will accelerate the wear of the tip. (I too tried this, and I would still do it this way for a single hole.)

My approach now is to first drill the wood with a multi-purpose bit using a cordless drill, and then to switch to the hammer drill for the masonry/concrete. Having both drills at hand with the correct bit inserted makes for fast and efficient work.

Switching drills at every hole will also remind you to switch your technique every time: with wood you apply moderate pressure so that the bit tip cuts; with the SDS hammer drill you apply no pressure, and instead "follow" the bit, so that the hammer does its work without over heating the tip.

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Not gonna happen. Because concrete is not a material that is drillable.

As you know, drills work by cutting with a sharp head - they peel off a layer, giving (under ideal conditions) a thin spiral of wood or steel.

That won't work on concrete or rock. Look at a classic hand mining - there's a long "drill steel" with a carbide tip welded on the end. It's shoved into the hole and hit on the tail with a hammer! The shock chips off some of the rock/concrete. Then a worker rotates the steel a few degrees and it's hit again with a hammer. This isn't drilling at all, it is chiseling, using the hole only to keep the chisel in desired position.

These two techniques are not compatible.

In fact, the tips are not compatible. Wood won't hurt a carbide tip, but rock or concrete will instantly destroy the cutting end of a wood/steel drill.

I would not send a wood drill into a hole that is full of concrete dust. You'd have to blow out that hole good and plenty, and still probably write off the drill.

Fair chance, however, that the concrete drill could simply be brute-forced through the wood. It would be messy.

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