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Left Hand Twist Drill Set

Don2222222

Plastic
Joined
Dec 7, 2013
Location
Wheatland, WY
Hi all,

I intend to buy a new set of Left Handed Twist Drills. Mainly to aid (as usual) in screw extraction for engine blocks and cyl. heads.

What brand(s) are your favorites... been a while since I‘ve shopped for any and my old set is getting stubby. Believe it or not they are an older set of Black and Decker from the 1980s... with alpha sizes instead of fractional sizes. Damn I‘m old...

Thanks, Don
 
I ordered individual sizes from McMaster. I use them exclusively for screw extraction and have only broken one so far. I just resharpened it: it is a bit shorter, but still works fine. As usual, for McMaster, I have no idea of the brand(s).
 
Any major brand.

Precision twist drill
Cleveland
Guhring
OSG
Dohrmer

Why is this even a question. I mean if you have the equipment to push a twist Drill, how do people not know which brands? Do people buy a Milling Machine and not know anything about Drills?

I understand this is more of a Mechanics question, but still.

R
 
Do people buy a Milling Machine and not know anything about Drills?
Surely. On the evidence, far too many don't even know anything about milling machines!

That said, drills aren't really the province of a milling-machine. Hand tools and drill press, more often, lathe now and then, mill more rarely.
I understand this is more of a Mechanics question, but still.

R

Yaabut.. extracting busted fasteners is NOT well-served by a LH drill.

Their "real" Day Job was/is for spindles with rotation as cannot conveniently be reversed. Metals OR woods. Only LH set we've ever owned or needed was to use a 1950's single-phase DeWalt radial arm woodchoppah's saw as a horizontal drillpress. 3-Phase model could have been easily reversed, not needed those.

In a motor or heavy equipment shop there's a need now and then to attack the busted end of a buried fastener to try to reverse it out as "sometimes" works, but a full-length chip-clearing helix back of the "biting end" only weakens the shaft. Better solutions exist, and no not just "EZ-Outs", those silly toys are more PITA than help, most any day of any week.

If it has to be drilled to flinders and dug out? Conventional drills usually work just as well, are easier to source, faster and less-costly to replace if trashed or busted.

LH twist drill? Izzat not a solution in search of a problem?
 
Yaabut.. extracting busted fasteners is NOT well-served by a LH drill.

for once i agree with you

once the drill bit grabs the work its going to either break the drill bit or break the work again when it feeds into the drill bit until something snaps. (presuming a mill or some such rather than a drill press)
 
for once i agree with you

once the drill big grabs the work its going to either break the drill or break the work again when it feeds into the drill bit until something snaps.

LOL! As with most humans who have managed to not KILL themselves early-on out of massive stupidity, we probably "agree" on better than 95% of "life in general".

We just seem to pick the small percentages to make war over!

That, too, is basic human nature, so I'm relaxed about it. Most days, anyway!

The other days? Blame some Irish genes. You know how it is with contrarians. The Irish never know exactly what it is they stand for, but are ALWAYS ready to fight you to the death OVER it!

:D

In the case of LH drills? Young guy hears it is a good idea, tries it, it works, he ceases looking for anything better, it becomes a habit, and in the fullness of time he becomes ta da willing to fight you to the death to defend the use of ..Irish drills! Naturally, he buys these from the English or the Germans.

:)
 
Left hand drill bits were/are? used on screw machines a lot.You have to reverse the spindle to get the tap out.
I actually spoke to a guy from FEW (french engineering works over here, they make decent stuff) not too long ago and he said that left hand drills are hardly ever asked for anymore for the reason you stated. Less guys with screw machines around.
He did say that when screw machines were all over the place that nearly 25% of their drills stocked were left hand.
 
Left hand drill bits were/are? used on screw machines a lot.You have to reverse the spindle to get the tap out.

Prezactly. That "inconvenient" to work the other way thing. Edge-case, in general, but FULLY justifying a proper high-grade drill for it, nothing even resembling junk admissible at the tasking and revenues involved. Better grades than average easily justifiable, actually.
 
Wow... I’m an old engine builder looking for LH Twist drills that will last. As stated, I have a Black and Decker set that I have used for about 30 years without breaking any... they are getting stubby from sharpening...

I was just wondering what brand you guys like... LH bits “aid” me in removing broken fasteners, they aren’t the solution.

To the members who question my methods... I grew up in a machine shop, setting up race engines with fancy valve jobs and deck heights... Now I am old and have a lesser need for such precision. It’s almost never done anymore. But when I can, I teach the younger guys.

I am familiar with a lathe and a drill press... Not a milling machine, but I still use fine instruments on a daily basis. Learned how to use them in the 1970’s.
I still fab things for different projects.

Sorry to have offended anyone with my primitive and archaic methods of metal work, which were passed on to me by the likes of the old machinists who taught me... when I was young.

I usually lurk in the forum, perhaps I should have stayed with that.

To the fine members who simply gave an opinion... thank you.
 
LH bits “aid” me in removing broken fasteners, they aren’t the solution.
No foul. We are on the same wavelength. They can be handy to have around.

I was just taught other methods first, preservation of the "expensive side" paramount, time not fussed over simply because it was so rare to need much of it, anyway.

Also how to "just go make" the tools to implement whichever any given extraction seemed best suited to.

If you truly are winding down to where "it's almost never done anymore"?

I'd just keep on "not using" the old ones. How many more goes does each have to deal with?

Unless they've changed the rules and it is "He who dies with the NEWEST toys wins?"

I which case I'm badly f**ked, the age of the "grave goods" I've accumulated!

:)
 
I'm one of those inferior automotive machinists too and often am hesitant to ask a question, for fear of a public shellacking. I have used LH drills for a long time with success, but only in the mill with slow spindle speeds and higher than normal downfeed pressure. As long as the drill is HSS, I think any brand is probably ok, especially since you've mastered the backwards sharpening technique..
 
I'm one of those inferior automotive machinists too and often am hesitant to ask a question, for fear of a public shellacking.
"Slow" doesn't make you "inferior". Just one of those annoying guys who does NOT have parts left-over after a re-assembly.
Anyway, it isn't actually shellac as it was in the old Indian Head era. These days you get Loc-Tite'd.

:D

I have used LH drills for a long time with success, but only in the mill with slow spindle speeds and higher than normal downfeed pressure. As long as the drill is HSS, I think any brand is probably ok, especially since you've mastered the backwards sharpening technique..

The left handed folk among us might ask "what do you mean 'backwards'?"

We Ambidextrous get more utility yet out of a drill by sharpening one flute each direction.

Whom did you THINK invented the "split point"?


:D
 
I have to disagree with you on the subject of screw/bolt removal. And I have tried almost all the techniques except those that involve wending or braising. Many of the things that I work on would not take kindly to the heat of welding or braising. It was my constant frustration with using things like easy outs or just drilling the screws/bolts out that lead me to the left hand drills. While using OTHER techniques that involved drilling, either for making the hole that an easy out requires or just plain drilling it out, that I came to the conclusion that standard right hand drills only served to tighten the screw in the hole. I have actually seen them go deeper into the hole while using a right hand drill. And just drilling them out often lead to an enlarged hole that then needed a thread insert. PITA!

SO, I purchased some left hand drills to drill those holes in the broken screws/bolts. I was thinking to use them before the easy out. The very first time I tried one, the broken screw came out in seconds. The easy out sat on the bench completely un-needed. That has happened virtually every time I have used a left hand drill on a broken screw/bolt. And I usually don't have to actually drill very deep. I have never used the easy outs again: I should throw then away for the storage space.

I do not use the left hand drills in a milling machine or even in a drill press. A hand held drill seems to work best as it allows the screw to back out.

Left hand drills are my first choice for a broken screw/bolt. I do not use them for anything else. Right hand drills do NOT work just as well. They tend to tighten the broken screw/bolt and that makes the removal job harder.

If you have a better technique that does not involve welding or braising I would love to hear it.



Surely. On the evidence, far too many don't even know anything about milling machines!

That said, drills aren't really the province of a milling-machine. Hand tools and drill press, more often, lathe now and then, mill more rarely.


Yaabut.. extracting busted fasteners is NOT well-served by a LH drill.

Their "real" Day Job was/is for spindles with rotation as cannot conveniently be reversed. Metals OR woods. Only LH set we've ever owned or needed was to use a 1950's single-phase DeWalt radial arm woodchoppah's saw as a horizontal drillpress. 3-Phase model could have been easily reversed, not needed those.

In a motor or heavy equipment shop there's a need now and then to attack the busted end of a buried fastener to try to reverse it out as "sometimes" works, but a full-length chip-clearing helix back of the "biting end" only weakens the shaft. Better solutions exist, and no not just "EZ-Outs", those silly toys are more PITA than help, most any day of any week.

If it has to be drilled to flinders and dug out? Conventional drills usually work just as well, are easier to source, faster and less-costly to replace if trashed or busted.

LH twist drill? Izzat not a solution in search of a problem?
 
I'm with EPAIII. Sorry, thermite, there are some folks (I am one) who think LH drills are pretty wonderful for removing broken fasteners. Never broken one in that application, either.

Yeah, they were intended for machines with inconvenient spindle rotation. That category includes multi-drill heads with internal gearing and no room for rotation-correcting idler gears, in addition to the things already mentioned. But that's not the only thing they are good for.
 
Wow... I’m an old engine builder looking for LH Twist drills that will last. As stated, I have a Black and Decker set that I have used for about 30 years without breaking any... they are getting stubby from sharpening...

I was just wondering what brand you guys like... LH bits “aid” me in removing broken fasteners, they aren’t the solution.

To the members who question my methods... I grew up in a machine shop, setting up race engines with fancy valve jobs and deck heights... Now I am old and have a lesser need for such precision. It’s almost never done anymore. But when I can, I teach the younger guys.

I am familiar with a lathe and a drill press... Not a milling machine, but I still use fine instruments on a daily basis. Learned how to use them in the 1970’s.
I still fab things for different projects.

Sorry to have offended anyone with my primitive and archaic methods of metal work, which were passed on to me by the likes of the old machinists who taught me... when I was young.

I usually lurk in the forum, perhaps I should have stayed with that.

To the fine members who simply gave an opinion... thank you.

Don't take it personally. The reason I sort of broke your balls about it, is that ANY decent Drill manufacturer has LH Drills. So LMGTFY. Here on this site B&D is not decent. 30 years ago they might have still been made in England (I think) but long since are now an export of China, so basically junk.

Meanwhile, it confuses the hell out of me when people get on an Internet forum and ask questions like; "what Metal is gooder". I've been around some other interests; Dirt Bikes IE. But I don't go on the Internet and ask; "how do you put gas in the tank?", "I can't drive it to the sip-n-tip." Maybe my Ego has the best of me, or maybe my Ego keeps me from sounding foolish :eek:
 








 
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