http://home.comcast.net/~bobengelhardt/drill1.jpg (37kB)
http://home.comcast.net/~bobengelhardt/drill2.jpg (43kB)

I found this bit at the dump. It has a tapered shank & is marked "star
- hammer - twist". It has a chisel point, not a cutting lip, so it
clearly does impact cutting & hence (?) is for masonry. But it is not
carbide tipped! It has some rust, so it can't be solid carbide, can it?

So, I guess the question is: is there some steel alloy that is used for
masonry impact drilling?

Thanks,
Bob

Bob Engelhardt fired this volley in
:

http://home.comcast.net/~bobengelhardt/drill2.jpg

Bob, I have four "star drills" in various sizes, none of which are fluted
for twisting like yours, but none of which have carbide tips, either.

The star drill has been the standard for decades for penetrating block
walls precisely and easily without a lot of spalling on the downwind
side. Just a gentle "tap-tap-tap-turn, tap-tap-tap-turn" and the hole
virtually makes itself.

The twist version allows you to clean out a blind hole, which a common
star drill cannot do.

LLoyd

Bob Engelhardt wrote:

http://home.comcast.net/~bobengelhardt/drill1.jpg (37kB)
http://home.comcast.net/~bobengelhardt/drill2.jpg (43kB)

I found this bit at the dump. It has a tapered shank & is marked "star
- hammer - twist". It has a chisel point, not a cutting lip, so it
clearly does impact cutting & hence (?) is for masonry. But it is not
carbide tipped! It has some rust, so it can't be solid carbide, can it?

So, I guess the question is: is there some steel alloy that is used for
masonry impact drilling?

Answer: Certainly, people were drilling masonry and rock long before
high tech materials like carbide were available.

"Bob Engelhardt" wrote in message
...
http://home.comcast.net/~bobengelhardt/drill1.jpg (37kB)
http://home.comcast.net/~bobengelhardt/drill2.jpg (43kB)

I found this bit at the dump. It has a tapered shank & is marked "star -
hammer - twist". It has a chisel point, not a cutting lip, so it clearly
does impact cutting & hence (?) is for masonry. But it is not carbide
tipped! It has some rust, so it can't be solid carbide, can it?


Most unlikely to be carbide - most likely a hardened high-carbon steel.

So, I guess the question is: is there some steel alloy that is used for
masonry impact drilling?


Hardened High-Carbon steel has been used for a very long time for masonry
drills - long before the invention of the power hammer-drill which this bit
would appear to be designed for use with - that were (and still are) used
with a hand-powered hammer. grin

BTW, are you _sure_ that you didn't mis-type the subject? A "gloat" would
also be appropriate for this bit. GRIN

On May 2, 12:25*pm, Bob Engelhardt wrote:
http://home.comcast.net/~bobengelhar...rill2.jpg(43kB)

I found this bit at the dump. *It has a tapered shank & is marked "star
- hammer - twist". *It has a chisel point, not a cutting lip, so it
clearly does impact cutting & hence (?) is for masonry. *But it is not
carbide tipped! *It has some rust, so it can't be solid carbide, can it?

So, I guess the question is: is there some steel alloy that is used for
* masonry impact drilling?

Thanks,
Bob

S7?
Maybe the bit is for drilling pavement.

On May 2, 12:25*pm, Bob Engelhardt wrote:
http://home.comcast.net/~bobengelhar...rill2.jpg(43kB)

I found this bit at the dump. *It has a tapered shank & is marked "star
- hammer - twist". *It has a chisel point, not a cutting lip, so it
clearly does impact cutting & hence (?) is for masonry. *But it is not
carbide tipped! *It has some rust, so it can't be solid carbide, can it?

So, I guess the question is: is there some steel alloy that is used for
* masonry impact drilling?

Thanks,
Bob

It's steel, not carbide.

The tapered shank of that bit fit into a hexagonal or octagonal
holder, maybe 6" long. The holder had a slot cut in it which allowed
you to use a wedge to remove the bit - just as in removing a Morse
taper bit. The holder was hit by a hammer, and rotated between hits.
The advantage of this over a regular star drill was that you could
have a big, solid shank on a small diameter bit. The bits were
sometimes spiral, sometimes straight.

By the way, common star drills ain't so common anymore. I needed to
hang a couple of shelves in the basement the other day. Figured 5/16"
screws would be fine, so I grabbed a box of machine screw caulking
anchors I'd had for years. Hmmm - full box. Hole size 5/8". Looked
for a 5/8" star drill. Plenty of 1/4", 3/8", 1/2", 3/4", 1" and
larger, but no 5/8". No problem, I'll just pick one up at the
hardware store. The third try - the biggest hardware store in
Portland, Maine, serves mostly commercial customers - actually had
three sizes. None of the sales people had any idea what a star drill
was, even in the store that had them. No 5/8", of course. So I ended
up using 3/8" screws, which need 3/4" holes. Now I knew why the one
box was full, and the other almost empty....

John Martin

On Sat, 3 May 2008 09:00:25 -0700 (PDT), John Martin
wrote:

On May 2, 12:25*pm, Bob Engelhardt wrote:
http://home.comcast.net/~bobengelhar...rill2.jpg(43kB)

I found this bit at the dump. *It has a tapered shank & is marked "star
- hammer - twist". *It has a chisel point, not a cutting lip, so it
clearly does impact cutting & hence (?) is for masonry. *But it is not
carbide tipped! *It has some rust, so it can't be solid carbide, can it?

So, I guess the question is: is there some steel alloy that is used for
* masonry impact drilling?

Thanks,
Bob

It's steel, not carbide.

The tapered shank of that bit fit into a hexagonal or octagonal
holder, maybe 6" long. The holder had a slot cut in it which allowed
you to use a wedge to remove the bit - just as in removing a Morse
taper bit. The holder was hit by a hammer, and rotated between hits.
The advantage of this over a regular star drill was that you could
have a big, solid shank on a small diameter bit. The bits were
sometimes spiral, sometimes straight.

By the way, common star drills ain't so common anymore. I needed to
hang a couple of shelves in the basement the other day. Figured 5/16"
screws would be fine, so I grabbed a box of machine screw caulking
anchors I'd had for years. Hmmm - full box. Hole size 5/8". Looked
for a 5/8" star drill. Plenty of 1/4", 3/8", 1/2", 3/4", 1" and
larger, but no 5/8". No problem, I'll just pick one up at the
hardware store. The third try - the biggest hardware store in
Portland, Maine, serves mostly commercial customers - actually had
three sizes. None of the sales people had any idea what a star drill
was, even in the store that had them. No 5/8", of course. So I ended
up using 3/8" screws, which need 3/4" holes. Now I knew why the one
box was full, and the other almost empty....

John Martin


My "ground rod driver" is an elderly Black and Decker hammer "drill"
No rotary motion at all, but simply bangbangbang. It came with a full
compliment of star drills and holders as well as the holders that you
grab and turn.

Works as good as a rivet gun for driving ground rods

$10 at an estate sale. In the factory metal box with all the
accessories


Gunner

Political Correctness is a doctrine fostered by a delusional,
illogical liberal minority, and rabidly promoted by an
unscrupulous mainstream media, which holds forth the
proposition that it is entirely possible to pick up a turd by the clean end.

If I had a SDS+ to heavy pipe - then mine would be also.
It is - ugh - drill or drill-hammer.

Put the pipe over the rod to protect the 'head' of the rod
and the pipe would keep you on the target.

It would be nice to have SDS hammer only - as there are some nice
spades and spears for digging and breakup of small stuff.

The heavy spade would be great to dig in hard clay.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Gunner Asch wrote:
On Sat, 3 May 2008 09:00:25 -0700 (PDT), John Martin
wrote:

On May 2, 12:25 pm, Bob Engelhardt wrote:
http://home.comcast.net/~bobengelhar...rill2.jpg(43kB)

I found this bit at the dump. It has a tapered shank & is marked "star
- hammer - twist". It has a chisel point, not a cutting lip, so it
clearly does impact cutting & hence (?) is for masonry. But it is not
carbide tipped! It has some rust, so it can't be solid carbide, can it?

So, I guess the question is: is there some steel alloy that is used for
masonry impact drilling?

Thanks,
Bob
It's steel, not carbide.

The tapered shank of that bit fit into a hexagonal or octagonal
holder, maybe 6" long. The holder had a slot cut in it which allowed
you to use a wedge to remove the bit - just as in removing a Morse
taper bit. The holder was hit by a hammer, and rotated between hits.
The advantage of this over a regular star drill was that you could
have a big, solid shank on a small diameter bit. The bits were
sometimes spiral, sometimes straight.

By the way, common star drills ain't so common anymore. I needed to
hang a couple of shelves in the basement the other day. Figured 5/16"
screws would be fine, so I grabbed a box of machine screw caulking
anchors I'd had for years. Hmmm - full box. Hole size 5/8". Looked
for a 5/8" star drill. Plenty of 1/4", 3/8", 1/2", 3/4", 1" and
larger, but no 5/8". No problem, I'll just pick one up at the
hardware store. The third try - the biggest hardware store in
Portland, Maine, serves mostly commercial customers - actually had
three sizes. None of the sales people had any idea what a star drill
was, even in the store that had them. No 5/8", of course. So I ended
up using 3/8" screws, which need 3/4" holes. Now I knew why the one
box was full, and the other almost empty....

John Martin


My "ground rod driver" is an elderly Black and Decker hammer "drill"
No rotary motion at all, but simply bangbangbang. It came with a full
compliment of star drills and holders as well as the holders that you
grab and turn.

Works as good as a rivet gun for driving ground rods

$10 at an estate sale. In the factory metal box with all the
accessories


Gunner

Political Correctness is a doctrine fostered by a delusional,
illogical liberal minority, and rabidly promoted by an
unscrupulous mainstream media, which holds forth the
proposition that it is entirely possible to pick up a turd by the clean end.


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