I suspect the OP has a rotohammer, a large machine that happens to
take SDS bits. Rotohammers/demoltion hammers typically take SDS
MAX or spline drive shanks. The smaller, lighter hammer drills
called rotary hammers take SDS bits. SDS usually kicks you into a
quality of bit that far exceeds straight shank bits that fit in
conventional chucks. Example drills that work well with SDS:
Bosch Bulldog, Hilti TE 7, DeWalt D handle. These drills will
all be rated for 1" bits or less. You are correct, the bit's
shank is much larger than the drill portion. Here is a pictu
http://www.dewalt.com/us/products/ac...ategoryID=4081
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______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"SteveB" toquerville@zionvistas wrote in message
news

Frank wrote in message
. ..

"SteveB" toquerville@zionvistas wrote in message
...

"Mike Dobony" wrote in message
...
I have used Bosh and DeWalt SDS bits and am having problems
with both. I
am using 5/32 for tapcons and they dull fast or break. the
Bosh seem a
little better, but not what they should be. Are there any
quality
alternatives to these two brands?

Mike D.

Do they make SDS that small? The SDS I have have
approximately a 3/8" shank.

Steve


http://www.amazon.com/s/ref=nb_ss_hi...2F32&x=19&y=17



Guess so. Dang. That's quite a neck down. My SDS is on a
Makita Rotohammer, and I have bits up to 1.5". Chisel points,
etc. I just had a hard time imagining that being used for a
Tapcon. I'd just use a small hammer drill for a tapcon. If you
snap one off, it surely has to cost less than an SDS of the same
diameter. (?)

Steve