Help tapping a hole.

[Monkeybear]

Hello,

I am trying to install a bullet guide in my Saiga x39. I drilled a hole though the trunion eaisly enough but had less luck with the tap.

I need to run a 6-32 tap though the trunion. The problem I am having is getting the tap to start tapping.

If I just turn the tap nothing happens. If I turn the tap and push down a little nothing happens. If I turn the tap and push down a little harder nothing happens. If I turn the tap and push down a little harder nothing happens......and then the tap breaks.

I used oil and turned clockwise. I have a new tap on order from Snap-On.


Any tips, hints or ideas? The Saiga 12 fourm seems to have come up dry.

 

[Howard Roark]

I'll bite.

Metal too hard or hole too small.

 

[Monkeybear]

I used the tap in my kit. Lots of people over on the Saiga forums have had good results with them. I will buy a new drill bit though and check the hole size.

 

[highorder]

if the screw isn't load bearing, you can cheat and enlarge the hole a few thousandths. you will lose a little holding power, but tapping will be alot easier. Also, what type of tap do you have, and what maker? Cheap chinese crap is no match for an American tap. Is the hole thru or blind?

 

[Monkeybear]

Hole though. HSS taps; don't know if those are good or not.

What size drill bit would I need for a 6-32 tap?

 

[highorder]

you need a #35 (.110")for 75% thread engagement, but you can probably cheat your way to a #31 (.120") depending on what you are drilling with. if you have a nice mill with little run-out, you can cheat bigger... if you are using a hand drill, I would stick to the #35 and let the chuck slop do the work.

what size drill did you use to begin with?

 

[Wildfire]

Taps.

Hey there:
start with a tapper tap, and if a blind hole finish with the bottoming tap.
A good starting block will help keep it in line. Also a very slight counter sink will help the tap get started.

 

[highorder]

+1 on the countersink. anything you can do to chamfer the hole will be a big help.

 

[moooose102]

Also, You May Be Using A Bottoming Tap Instead Of A Starting Tap. A Starting Tap Has Much More Taper To It (easier To Start). But To Be Honest, It Sounds To Me Like You Are Not Using The Propper Size Drill (i Think You Are Using To Small Of A Drill). You Need To Be Carefull When Doing These Types Of Things To Guns. If You Make A Mistake, Its Going To Cost You A Lot More To Have A Gunsmith Repair It Than It Would Have To Have Him Drill And Tap It Right The First Time. Drilling And Tapping Is Not Something A Gunsmith Charges A Lot To Do. Just Something To Think About.

 

[highorder]

say moose, I'm from western Michigan, and we don't capitalize every word.

what gives? are you using a funky text editor?

 

[Monkeybear]

Thanks! Thats alot of help guys. Just one more thing though, I am having a hard time locating a local or online store that has taps.

Know of a good online store that sells them?

Thanks again!

 

[hoghunting]

Brownells carries a wonderful selection of gunsmith supplies, including drills and taps.

http://www.brownells.com/

 

[Wildfire]

Metal.

hey there:
I should add , if you drilled that metal, it is not too hard to tap. But I agree also that the hole may be the wrong size.

 

[brickeyee]

MSC has taps at (usually) better prices than Brownells.

Brownells is the 'go to' place for the odd taps often used in firearms though.

It really sounds like you tried starting with a plug or bottoming tap.
A taper tap has a longer lead in to start threading.
Follow it with a plug and then a bottoming for blind holes, or run it all the way for through holes.

You can hold taps in the drill press and use the quill feed to get them started if you turn the chuck by hand.
DO NOT USE THE MOTOR.
Once the tap has started you can loosen the chuck and put a T-handle on the tap to finish up.
You WILL need tapping oil (or wax) to get decent threads and not break the tap.
A piece of scrap metal of the same type as the finished product can be handy to learn on.

 

[highorder]

I use Tap-matic fluid for steel.

I get my taps from www.jlindustrial.com or
www1.mscdirect.com/

 

[Monkeybear]

Thanks for all your advice guys!

My order for a tap from Snap-On was canceled for no apparent reason, guess $4 is not enough for them to go though the trouble of shipping something?

Anyway I got an Irwin tap at Home Depot that claims to be made in America. Worked like a charm! Don't know why but this time it was easy breezy and took maybe two minutes to go though the trunion.

 

[highorder]

American made machine tools really are better that asian import crap.