Ever break a tap?

[gstrom99]

It's not on a tractor, but...

I finally got my two post car lift installed and started to wire it. I wanted a "motor disconnect", so I needed to attach that box to the column. The installer advised that nothing can protrude inside the column where the lift pads run, and don't bother trying any "self tapper screws" - they'll just break off. So, I drilled and started to tap threads for 1/4" short bolts. I got one done, and on the second one, the tap broke when almost through. I think I ordered a good extractor from McMaster Carr: McMaster-Carr should be here tomorrow.

It's easy access. How successful are these tools?

 

[ruffdog]

They do work...on straight flute taps. Get the ones that match how many flutes you have. If you start to bend the prongs, lightly tapping the broken piece this way and that way first with a small punch may loosen it enough. Keep the extractor as close to the broken tap piece so the prongs are the strongest.

 

[Beaver Cove Deere]

As a former tool and die maker don’t use a 4 flute tap whenever possible.
2 flute machine taps are much more robust.
#7 (.201) is the tap drill size.

 

[5030]

depends on how heavy handed you are and next time drill the hole one drill size larger than the specified tap drill. as what you are attaching isn't holding any weight or providing support. Taps wear out and then the force to drive them overcomes the strength of the tap and then they break and use some lubricant as well. any light oil is just fine and when hand tapping, screw the tap in a full turn and back it of 1/2 turn to break the chip the tap is cutting. Full turn, 1/2 turn and repeat.

 

[ruffdog]

As a former tool and die maker don’t use a 4 flute tap whenever possible.
2 flute machine taps are much more robust.
#7 (.201) is the tap drill size.

Agree...also, spiral flute taps seem more robust too.

 

[ArlyA]

Gee, over the years I broke more taps than I care to recall. Doesn't everyone? As others have stated, use the next larger drill than suggested.

 

[5030]

Spiral flute taps are more of machine taps than hand taps. I use them all the time when semi production tapping. Broke a few of them as well. Sometimes I'd like to have a wire EDM machine to remove them without scrapping the piece.

 

[2manyrocks]

Sometimes I weld a nut to the metal to avoid tapping anything.

Worst case is the extractor breaks and then good luck drilling that hardened metal out.

 

[buckeyefarmer]

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

 

[pmsmechanic]

For what the op is doing I would take a punch and just push the tap out the rear of the hole. Then start over with a new tap. He isn't holding much and that will work just fine. You could always use a Heli-coil if the hole has to be perfect.