Broken tap removal

[machinisttx]

I know alot of guys in the trade that will only roll form threads. They claim they give the best tool life on stainless steels, etc.

Only problem with roll form taps is getting the drill size correct. They generally last nearly forever though--most I've seen and used were carbide.

 

[jrhines]

I think a THR guy told me this...

but I only use a tap once on a customers gun (taps are cheap), and I "pre-break" it by Dremmeling a groove about half-way up and completely around the shank with a cut-off wheel. That way, if it breaks, it will break at the groove and leave plenty of length to get the thing out. For even high quality taps, the price is so low that the extra expense far outweighs the potential problems of removing a tap broken off below the edge of the hole.
I buy taps from Brownell's, typically six at a time. When I get down to three, I get six more. I keep all the usual gun sizes on hand (all 14 of 'em) and I have some of all three types in most all the sizes. Comes in Handy! YMMV

 

[plinky]

Transmission fluid is not cutting oil, neither is WD40, or any of the other crap folks try to use. Proper cutting oil(Brownells "Do Drill", tap magic, etc.) and a new, spiral point taper tap would have more than likely kept the tap from breaking.

Yes, I see that now. I wasn't advocating the practice, just counting my lucky stars that it worked out alright.

 

[jmorris]

spiral point taper tap would have more than likely kept the tap from breaking.

Spiral flute taps are great for gummy and/or soft materials(aluminum for example), but don't work very well in hard alloys and are more prone to breakage since

Wow less that 3hrs to change positions are you a dem?

 

[Clipper]

I don't care much for Tap Magic either. The stuff I really like is called Anchor Lube. It's water based, and non-toxic, and works really well. When I don't have any handy, I use a 50-50 mix of 30 weight oil (Kendall GT-1 in my case, as it's what I use in my cars) and Dura Lube. Works pretty well.