masonry drill warning


rec.crafts.metalworking
masonry drill warning
Anyone know why a 1/4 masonry drill has a warning "don't use on a drill press"
? This came from a local hardware store.
Hul
Reply to
Hul Tytus
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Its mandated there by the same people who put "don't touch moving blade" on chainsaws. And its a vain and futile attempt to protect the really dumb from themselves - it usually doesn't work (ie, they don't/ cant/wont/ read the instructions) and the lucky ones get nominated for Darwin Awards.
Just my opinion, of course. Sorta makes sense.
Andrew VK3BFA
Reply to
Andrew VK3BFA
It's been my experience that a carbide tip breaking off is safer when it happens in a hand drill, away from your face, than in a drill press at chest or eye level. YMMV
Reply to
Steve Walker
I have no idea, and I have used masonry drills in a drill press to drill through hardened steel. Very noisy, boils the coolant and nonetheless ruins the drill, but it does work.
Joe Gwinn
Reply to
Joseph Gwinn
Mandated by the same civil servants that put a warning label on a bag of peanuts saying "warning, contains peanuts"
Reply to
sparky
I have a tube of bandsaw blade wax that warns not to apply it to a moving blade.
jsw
Reply to
Jim Wilkins
If it's your typical Vermont American double flute, I've found the shanks on some are soft enough to be bent over by hand while chucked .
Couple of guesses..in a hand drill they are free to drift a little when hitting the edge of aggregate. Could also be an issue with the powder jamming the bit in the hole.
Reply to
Rick
Masonry drills are designed for slower speeds and hammering action. Using these bits in a drill is not the best idea because you'll need a good jig to hold your workpiece down. Most people can't design a jig. Also masonry bits tend to crush during cutting which makes them a poor choice to use on a drill press because they'll walk or skate unless you apply lots of pressure. It's easier to apply pressure by using a hand drill/hammer drill than many small home shop drill presses. They seem a bit dangerous to use on a press.
Reply to
The Henchman
masonry bits, as supplied have a significant negative rake cutting edge. they are meant to be used in a hammer drill with brittle materials. As supplied they will perform very poorly on any metal. If you know enough to re-sharpen them correctly for use when drilling hardened steel, you know enough to safely ignore the warning :-)
Mark Rand RTFM
Reply to
Mark Rand
I'm speculating, but maybe with the cutting geometry of a masonry drill, they are concerned that a drill press will cause enough friction to loosen the bond between the carbide and steel body.
Masonry drills are not very sharp.
Wes -- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller
Reply to
Wes
It's difficult to balance the masonry on the drill press table? :)
Reply to
T.Alan Kraus
because you're supposed to use then with a hammer drill, not a drill press.
they work by crushing concrete or whatever, not cutting into it.
If you don't believe it, just look at the tip. There's nothing cutting or sharp about it.
With a hammer drill you can drill masonry with regular bits, but they will break quicker.
Reply to
Cydrome Leader
Might be a case of chipping carbide towards an eye that got them in trouble.
No matter what you do, at a drill press stuff cuts and chips and flies.
Use an apron, face shield and ear protection and then some.
Martin
Hul Tytus wrote:
Reply to
Martin H. Eastburn
I can just see a finger pushing the wax onto the blade....
Martin
Jim Wilk>> >>> Anyone know why a 1/4 masonry drill has a warning "don't use on a drill press"
Reply to
Martin H. Eastburn
Or running at 8,000 RPM in a three pulley wood/steel model. Martin
Rick wrote:
Reply to
Martin H. Eastburn
It is nice to say it is a hammer-drill made product - now maybe sometimes.
I have a hammer drill now - a 1/2" SDS+ with a chuck as well. Before that, I used a regular 3/8" slow slow speed drill. One drill I wish I still had.
Those drills are older than hand drills. I have a 3/4" 12" carbide drill. It was for drilling through a 8"+ floor. My dad bought it in the late 50's. The shaft to chuck up is smooth round. It is designed to slip. He used his 1/2" death defying hand drill with gear train and it had to be piped to something and held. If the drill caught and wrapped the drill around it would keep turning with the power off for a number of turns.
My hammer is electronic control and is fast stop.
Martin
Mark Rand wrote:
Reply to
Martin H. Eastburn
Come on Jim, everyone knows that's what earwax is for. Just make sure to remove it from the ear, first. ;-)
Reply to
Michael A. Terrell
He may not have a rotary/percussion bit..there are common "hardware store" masonry bits that are for rotary use only, as shown here:
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Reply to
Rick
I have done that on one occasion when I thought I'd hit a bit of quartz in the concrete that turned out to be an unexpected re-bar. After making no progress for some time and leaning on the drill as hard as I could, I pulled the bit out of the hole and saw that the end had gone blue and the carbide fell out of the slot it was brazed into...
Mark Rand RTFM
Reply to
Mark Rand

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