masonry drill warning

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

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

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

Mandated by the same civil servants that put a warning label on a bag of peanuts saying "warning, contains peanuts"

I have a tube of bandsaw blade wax that warns not to apply it to a moving blade.

jsw

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.

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.

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

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

It's difficult to balance the masonry on the drill press table? :)

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.

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.

Mart> rec.crafts.metalworking

I can just see a finger pushing the wax onto the blade....

Mart> >>> Anyone know why a 1/4 masonry drill has a warning "don't use on a drill press"

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:

Come on Jim, everyone knows that's what earwax is for. Just make sure to remove it from the ear, first. ;-)

He may not have a rotary/percussion bit..there are common "hardware store" masonry bits that are for rotary use only, as shown here:

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