Another broken tap question

[Milsurps 4 Me 14]

So I heard it happens to everyone at one time or another and tonight I snapped a tap in my 5.45 round trunnion. I can't get it out no matter what I've tried including whacking the tap with a punch to shatter it. I figured since it was a carbon steel tap it would shatter easily but I think its just too thin and theres too much of it. Its all the way through the trunnion. I even tried gently backing it out with needle nosed pliers from underneath but the tip that was sticking out snapped flush.

 

Is there any other way I can install the bullet guide?

[paprotective 362]

I used an icepick to whack mine out..

 

some have successfully used JB Weld to hold the BG in..

 

though not the #1 way.. I have seen it done on here ALOT..

[jimdigriz 580]

It took a lot of perseverance, but I eventually got mine to crack by whacking on it. Had to try punches of different profiles, and ruined a couple of them in the process. Is your punch flat or pointed at the end? The flat one worked best for me, since, as you say, the tap is very thin.

[Milsurps 4 Me 14]

I bent the hell out of a few flat punches and even broke one. I went at it for about 10 minutes with them. I'm not too concerned with enlarging or ruining the hole because I plan on going up a size or worst case using the rivet that came with the Bulgarian guide.

 

I'll look for a few better punches today at the local hardware shops. I haven't totally given up yet but am wondering about other options just in case.

 

 

Has anyone ever welded a guide in place? I was thinking if I couldn't get the tap out maybe I could use a mig welder on it and put a few tack welds where the hole is in the guide.

Edited March 6, 2011 by Milsurps 4 Me

[TonyRumore 1,332]

I have welded them in place before, but it doesn't look all that great and it's hard to clean up the weld being down in the recevier like that.

 

I would try to break up the tap using a tapered nail set instead of a straight pin punch.

 

Tony

[Milsurps 4 Me 14]

Doing a search on broken taps I found a machinists forum where some people mentioned diamond bits to remove the tap. I ended up getting a small thin Dremel diamond particle covered bit from Home Depot and decided to try it last night.

 

After making contact with what was left of the tap I began to notice fine grey powder residue building up and knew it was working. I kept blowing off the residue with a can of compressed air so I could see what I was doing and in about 2 minutes I had gone deep enough to see a small hole where one of the flutes was. I dug the point of the bit in there and started working towards the rest of the tap and managaed to remove almost all of it. Then I clamped the receiver down in my drill press and with the drill bit that came with the tap combo set was able to clear the rest of the bits of the tap from the hole with ease.

 

I ended up going with a drill bit that came with a combo kit for an 8-32 tap and used a tap I got from Snap On and had success installing the bullet guide.

[mxwelch 15]

Not diamond but carbide. You can get a carbide bit for a dremel and carefully cut thru the center and then use a pick to get it out. Needless to say the smaller the tap the more difficult it is. A carbide endmill in a press works well. If you're careful and don't mill out the minor diameter of the threads then when you get it out you can retap it.

[misterT 174]

It is VERY difficult to tap hardened steel, i usually drill the hole slightly oversize and tap very slowly only about 1/8 of a turn at a time backing the tap up to beak the chip each time and backing the tap all the way out each full turn to clean up the chips. Use LOTS of tapping fluid or a good oil and be careful to keep the tap aligned. I often keep the workpiece in the vice aligned up and put a center in the drill chuck and lower it into the center hole on top of the tap handle to keep it straight.

[ktz784 0]

File the remainning tap down, leveled with the trunnion. Then jb weld the bullet guide.