Ever break a tap?

[jgmo]

Well....I don't have tons of advice to give about taps or drilling that would be any better than what's already been offered here.

And I have zero experience. with the extractor you ordered.

Just wanted to tell you about a tool called RESCUE BIT.

It's for "digging out" broken fasteners, taps, drills from holes you need to save and use.

It is relatively expensive.

But, as a long time mechanic, it's another one of those tools I wouldn't be without.

And they last IF you follow the directions provided.

They come in several shank sizes including 1/8" that fit Dremel chucks and collets.

Good luck.

 

[charlessenf]

I needed to attach that (switch) box to the column

Years ago I attached a 12VDC oscillating fan to the 'ceiling' of my Chevy G20 Van. The mounting bracket was drilled but there was NO WAY I was going to drill matching holes through the ceiling/roof of the van. The bracket was a one inch square with channels to hold the fan mounting plate. I had some 3M 5200 Marine Sealant and spread a dollup of the stuff where i wanted the mount and pressed the bracket in place.

I left it for couple of days before mounting the fan. Five or six years later, junking the van to make the wife happy, I removed the fan from the bracket and began removing that little piece of steel.

Jeeze, the effort required! Finally, a length of piano wire and a pair of vise grip piano wire holders let me salvage the bracket.

I have repaired my boots with the stuff - but do NOT buy in bulk because it has an actual shelf life and can solidify in the unopened container on you shop shelf. Better to purchase as close to the actual quantity required as possible.

"3M Marine Adhesive Sealant 5200,, White, 295 mL, 1 Cartridge, Watertight Bonging/Sealing of Gelcoat $33.10 Walmart 3M Marine Adhesive Sealant 5200,, White, 295 mL, 1 Cartridge, Watertight Bonging/Sealing of Gelcoat - Walmart.com"

 

[akajun]

If it’s a through hole and you have a plasma cutter , simply turn it up and blow it out with a quick pull of the trigger
Next option is the same but with a cutting torch
Last option , weld it out with washers and nuts and unscrew it

Tap extractors never work if you broke off the tap from binding, which it sounds like you did

 

[charlessenf]

That's generally true for end mills for the non-production type machine shop, don't think that necessarily applies to taps

OFF TOPIC but, since you motioned END MILLS and I need to put a shallow 5/8" diameter locating 'hole' in a hunk of 1/2" thick steel to serve as the support plate laid up against the Floor Joist beam(s).

I wonder if I could mount a 5/8" diameter End Mill in my 5/8" drill chuck and use it as I might a standard drill bit to bore a shallow hole in the steel plate.

Maybe lower the RPMs to ??? and use plenty of cutting oil?

Possible? Plausible? Pitfalls?

Anyone jnow for certain?

 

[MTGreen]

OFF TOPIC but, since you motioned END MILLS and I need to put a shallow 5/8" diameter locating 'hole' in a hunk of 1/2" thick steel to serve as the support plate laid up against the Floor Joist beam(s).

I wonder if I could mount a 5/8" diameter End Mill in my 5/8" drill chuck and use it as I might a standard drill bit to bore a shallow hole in the steel plate.

Maybe lower the RPMs to ??? and use plenty of cutting oil?

Possible? Plausible? Pitfalls?

Anyone jnow for certain?

Yes it's possible, especially if you are trying to make a perpendicular hole. Use the lowest speed the drill press will go, cutting oil, and make VERY sure everything is clamped down as best you can make it -part, vise, and table too. Understand that you will need to put some constant pressure on the end mill as the cutting forces will cause the mill to pull down and the chuck may pop out of the mating taper which can be a hazardous situation. Use a 4 flute HSS center cutting end mill - if you can't find a center cutting one in that size, you will need to make a small hole in the center to compensate before plunging the end mill.
If you're trying an angled hole, you likely will have less success as the drill press table is not set up to contain lateral forces and you are likely to break your end mill.

Also if you are making a through hole or you don't need a flat bottom to the hole, you are better off with a silver and Deming type reduced shank drill bit

 

[charlessenf]

Use a 4 flute HSS center cutting end mill - if you can't find a center cutting one in that size, you will need to make a small hole in the center to compensate before plunging the end mill.

Yes, perpendicular into 1/2" steel plate < 1/8" deep

if you are making a through hole or you don't need a flat bottom to the hole

Right, may not NEED a flat bottom hole, but prefer it.

End Mill, 5/8" 4 Flute, HSS, 1/2" shank​

When they list 5/8" X 5/8" the first value is the cutter and teh second is the shank, right?

I am not certain my chuck will take a 5/8" diameter shank!

 

[MTGreen]

Yes, perpendicular into 1/2" steel plate < 1/8" deep

Right, may not NEED a flat bottom hole, but prefer it.

End Mill, 5/8" 4 Flute, HSS, 1/2" shank​

When they list 5/8" X 5/8" the first value is the cutter and teh second is the shank, right?

I am not certain my chuck will take a 5/8" diameter shank!

Yes cutter diameter first followed by shank diameter. Many 1/2" chucks open up a bit more than 1/2 -heavier drill presses commonly have a Jacobs model that opens to 5/8.
That pictured one looks like a reduced shank likely 1/2" if that is a pic of the actual product

 

[LD1]

That's generally true for end mills for the non-production type machine shop, don't think that necessarily applies to taps

Not really even true for end mills. Flute count dont matter too much for various materials. But flute angle is often different for aluminum specific end mills. (or non ferrous).

But 2-flute is the common go-to for precise slotting or key-way milling. Because 4-flute tends to mill a little oversized and/or offset the slot from where you actually want it by a few thousandths

OFF TOPIC but, since you motioned END MILLS and I need to put a shallow 5/8" diameter locating 'hole' in a hunk of 1/2" thick steel to serve as the support plate laid up against the Floor Joist beam(s).

I wonder if I could mount a 5/8" diameter End Mill in my 5/8" drill chuck and use it as I might a standard drill bit to bore a shallow hole in the steel plate.

Maybe lower the RPMs to ??? and use plenty of cutting oil?

Possible? Plausible? Pitfalls?

Anyone jnow for certain?

I didnt see any mention of a drill press??

Yes you can do it in a RIGID press. But if you are thinking free-handing a endmill in place of a drill, forget it. Ever try a hole saw without a pilot bit.....basically the same thing

 

[MTGreen]

Not really even true for end mills. Flute count dont matter too much for various materials. But flute angle is often different for aluminum specific end mills. (or non ferrous).

But 2-flute is the common go-to for precise slotting or key-way milling. Because 4-flute tends to mill a little oversized and/or offset the slot from where you actually want it by a few thousandths

I didnt see any mention of a drill press??

Yes you can do it in a RIGID press. But if you are thinking free-handing a endmill in place of a drill, forget it. Ever try a hole saw without a pilot bit.....basically the same thing

I suppose I should have said "hobbyist" shop here as opposed to "non-production", thanks for clarifying.
And yes good point I assumed a drill press!

 

[zzvyb6]

I use mine for lawnmower storage & maintenance.

 

[Gord Baker]

Just start in a new spot or use metal banding to attach whatever you are mounting.

 

[Fields_mj]

Admittedly, I read the first page and jumped straight to page 6. I'm sure you're already fixed this by now, but IMHO you have 3 choices. First, if its an expensive part that you can't afford to start over on (I know you are not in this category), take it some where that has a plunge EDM so they can burn it out.

2nd option is to smash it with a hammer and a punch, and try to pick out the pieces. It's a PITA, and you risk damaging the threads which could require you to install a helicoil as part of the fix. Keep in mind that the tap is extremely hard and will damage your punch.

3rd option (this is what I would do in this application), smash it with a big hammer until nothing sticks out past the surface. Move everything 1/2" over and start again (or leave it in the same spot an use a different hole). FWIW, if the threads are not critical (ie, you plan on stretching the bolts appropriately to keep them from coming loose) always go at least one size bigger on your drill bit when you're tapping by hand. In this case, use a #6 drill bit instead of a #7. The extra few thousandths of an inch makes a big difference in how much effort is required. The more effort you're putting into it, the more likely you are to make a mistake and break a tap. Realistically, for a 1/4-20 tap on this application, you could easily use a #4 drill bit.

Also, make sure you're using an appropriate tapping fluid. For most applications, you don't have to get real fancy. I generally use ATF for mild steel and WD40 for aluminum.

 

[RandR10]

I've only ever broken a few taps over many years of using them. Usually not in blind holes, so putting a pair of vice grips on the other side and screwing it back out of the hole usually works for those. You should be able to do this if you drilled the hole clear through the side of your lift column. If not, read on.

The one tap I broke in a blind hole was in the head of my Bridgeport-clone mill the day I brought it home. Someone had broken an oiler off the side, and I messed up the threads pulling that out, then promptly wedged a broken tap back in the hole. I used a die grinder to flatten the jagged break, then worked at it for several hours with a few diamond core bits on low speed in the drill, keeping it wet with water the whole time. Eventually I got through the flutes to the taper, and with the pressure off the cutting edges no longer holding it tight in the threads, I backed what was left out of the hole with some mini needle nose pliers.

Moral of the story, don't use cheap taps, especially not in blind holes. I didn't have that size in my good ones, so like a fool I used a tap out of an old cheapo set someone had given me years ago, rationalizing to myself that all I was doing was cleaning up the threads. Boy did I pay for that mistake. I've used cheap taps where the metal is too soft. Those just don't cut and will actually twist instead of breaking because they were never hardened. Other cheap taps are too hard and brittle and will just shatter like this because they weren't annealed after hardening.

 

[gstrom99]

Tap extractors never work if you broke off the tap from binding, which it sounds like you did

This one did. The backside had to be smooth, so the column could slide up inside. All fixed, and wired, and working great.

 

[Flogger]

did break an easy out in a bolt once. I got it out by paying someone else...

My wife discourages the use of my paying someone else tool!!

 

[coast40]

I broke a 4-40 tap off in a small piece of aluminum a few years ago, and after some internet searching, I found a method using a concentrated alum solution. I mixed it up in a glass beaker and dropped the aluminum piece with the broken tap into it, and the next morning the tap was completely gone and the aluminum unharmed. Obviously though, that wouldn't work on a steel work piece.

I plan on doing this with a broken Irwin EZout stuck 40 years ago in a '59 Corvette 4 speed.

 

[gstrom99]

I plan on doing this with a broken Irwin EZout stuck 40 years ago in a '59 Corvette 4 speed.

Interesting. Let us know how that works, with pics...

 

[1Mech]

Have you seen these?

The Metal Disintegration process for removing Broken Bolts

Not sure what metal disintegrator is for you? Here are 5 easy steps to choose the right metal disintegrator to remove broken bolts

electroarc.com

I have used those when I worked in a machine shop years ago. Get it centered over the broken tap or drill bit and let it do it's thing. Similar to an arc welder, but instead of adding metal it eats it away!