Spline vs. SDS Max Rotary Hammer

JimMorrissey · Aug 4, 2005

Can anybody tell me how SDS Max compares to Spline rotary hammers......?

I have a Bosch SDS Plus rotary hammer and it just is not doing the job. I need to be able to drill 1" holes in rock about 8" deep.

Thanks.

_RaT_ · Aug 4, 2005

It won't be the drive that is limiting you, that is more a matter of convenicence and brand. SDS is typically found on the smaller drills but is a great drive system and wears very little over the life of the bit. I think Hilti came up with SDS and then Bosch with SDS plus. Your problem may well be the material you are drilling and the size of what your using to drill it. Solid rock still has to fracture in order to drill. The problem I see most folks have is they push to hard closing the air gap in the hammer mechanism. Once you have done that, you can no longer fracture the rock by a hammer action. Let the weight of the drill and your arm do the drilling. You will know if you need to add a little more weight if the drill constantly hops. Now if your serious about drilling holes, rent a rock drill. It is a drill run from a large compressor like that used for jack hammers. It has a cross shaped carbide head and a air hole running down the center to blow the cuttings out. There are no flutes. It is so fast that once you use it, anything electric is painfully slow.

jmc · Aug 4, 2005

The condition of the drill tip is at least as important as the drill motor.

hobbyfarm · Aug 4, 2005

Ditto,
what they said.
It may just be the bit (or rather the point) of the bit rather that the drive mechanism.

wroughtn_harv · Aug 5, 2005

I have a Hilti TE75 with SDS max. It's a hoss.

Don't ask me how they do it. But Hilti engineers their bits where they just cut better than the other manufacturers.

So my suggestion is to bite the bullet, sacrifice the wallet, and buy a Hilti bit, cuss like an off colored step child, and then do what you've been wanting to do. You just can't do it on the cheap.

HD in our area rents and sells Hilti. If they do it in your area I'd suggest renting a big Hilti and a bit and try out the combination.

I paid eight hundred for a TE15C when I could have bought three Bosch or DeWalts for that price. I was cutting in thousands of holes in six thousand psi concrete and was tired of going nowhere quickly. Like I said, I can't explain it. But that TE15C cuts faster and easier.

I've had the same results from the TE75. But of course I bought the TE75 because I'd had great luck with a TE74 and a bud who'd borrowed it offered me more than what I'd orginally paid for it. So I upgraded to the later model.

Tevi · Aug 6, 2005

</font><font color="blue" class="small">( I have a Hilti TE75 with SDS max. It's a hoss.

Don't ask me how they do it. But Hilti engineers their bits where they just cut better than the other manufacturers.It's in the carbide tips and the dual groove twist that removes the material alot faster.Hilti is the way to go SDS is easier to get.I have a Milwaulkee spline that works great but the bits are harder to find