Technical reverse-twist drill bits......

When using reverse twist drill bit (when trying to remove a broken stud/bolt) do I also run the drill in reverse or......run it forward?
6sally6

 

Run the drill in reverse.

 

Won't work as intended if you run it clockwise= forward.

 

There’s kind of a feel that goes along with it also. The drill is spinning the opposite direction and you need to put some down pressure on it and when the bit catches and the bolt starts to turn out you need to allow it to come out. If using a hand drill it’s not bad but in a drill press or mill things can get fetched up and you’ll be trying to remove the broken bolt with a broken bit in it.

 

Works better with a Jacob's Chuck.

 

TIG weld a nut on the end of the broken stud and use a wrench to back it out. Have plenty of nuts on hand as you may have to do this 3 or 4 times. It has always worked for me.

 

Let me add my $0.02 worth...Before you weld a nut to the broken bolt..... Weld a flat washer to the bolt...weld the nut to the washer...Bobs Yer Uncle
Keeps from welding the broken bolt to whatever its in..

 

I also like to grind off the cad plating before welding. You'll get a stronger weld

 

I often use left hand drill bits in a Bridgeport for extracting broken screws at work. On the occasion that I can't, I make a drill guide to keep it centered over the broken fastener. A good soaking with penetrating oil helps a lot, too.

 

FYI: They are called Left Hand drills.

 

Is that right? Lol

 

Yes they are. I used to sell them at O'Reillys

 

Only thing that I've found that works consistently for a broken bolt is heat. Drill a hole and use a regular easy out on a glowing red broken stud.

 

"Easy outs" have never been my favorite method for removing broken bolts..... There's some basic instinct that tells me that screwing or pounding a tapered object into a straight hole with the intent to un-screw a fastener is self defeating.... the wedging action just makes the fit between the tapped hole and the fastener tighter. Drilling with progressively larger drill bits works best for me, although Left Hand Twist Drills make the most sense. JMHO

 

I find the left-handed bits work better than EZ outs. Never had much luck with them.

 

EZout is a big misnomer

 

EZ outs are a great way to turn a small problem in to a bigger one. Drilling out a broken EZ out sucks even harder than drilling out the broken bolt you started with.

 

THIS
I have even removed studs that had broken off below the surface. This saved me removing the head from my motorhome engine, using a MIG welder.

 

Sometimes you just have to find a shop that has a disintegrator...........

 

exactly ^^^^^^

The idea is that the drill will hang before it breaks out and spin the broken bolt or stud out.

 

A snapped EZout is the hardest known substance to man. Makes diamond and carbide look like butter.

They are good for pulling out main discharge jets (not main metering jets!) from Strombergs though.

Cheers,
Harv

 

Left hand drills are usually screw machine drills. Shorter is better than longer, unless you need the reach.

 

Has anyone been successful using a left twist drill bit to get a broken bolt out?
I’ve never used one before.
But….begs the question if you’re going to tap a hole and use a left hand thread, I can see using a left twist bit.
Cmon. Someone was gonna say it.

 

they should NOT be called easy outs.

they should be called HAHA Your fucked !

 

Yes, I have. Mostly on smaller diameter aircraft fasteners; though I've managed to do it on automotive parts also. Pretty slick... when it works.

 

X-2!

 

At work, we call them Fuck you Overs!

 

If you buy your “EZ Outs” from HarborFreight, and break one off, they are easy to drill out because they are made of wood!

 

Just a small thought here. Years ago I was working in a Lincoln-Mercury dealership and the guy next to me snapped a bolt off in a Capri V8 fuel pump mount. He was panicky about how to get the broken bolt out. I offered to let him use my reversable air drill and my left handed drills. I told him that most of the time the broken bolt would unscrew itself once the drill broke through the end and caught the tip. Off he went and the next thing I hear is him screaming loudly. I run over and here he is with his hand pin he'd between the frame rail and the air drill. He was in tight quarters and when the drill broke through, it spun the bolt shaft out as fast as the drill was turning and squashed his hand. Word to the wise, only put enough speed and pressure to get the screw out. Don't lean on the drill full force and hold the trigger wide open. It could be painful!

 

On a side note, I read somewhere that Henry Ford used left hand drill bits in the factory to keep workers from stealing bits.