10/24 threadmill

[Joels]

Anybody know where i can get a 10/24 threadmill thet will go to a depth of .750? i need to tap steel on a blind hole so i thought this would work well but i cant find one that will go pasr .312 deep

[Harryman]

I don't think such a tool would be very successful. Form tapping will work better than thread milling in a deep blind hole.

[Metalmuncher]

How about a roll tap they work very well on blind holes

[Mike Whitten CAD/CAM Contractors]

I agree with Harry and Metalmuncher.

 

Form it. I love the OSG nrt taps 1.5p lead, they are inexpenive and work great.

 

I always tap when I can, it's generally just easier.

 

Mike

[Joels]

a stupid question. I did form tapping in aluminum but this is steel and i dont know what grade but it is not really hard. the question is since forming the thread is smashing it wouldnt that be harder to do that cut the thread?

[Guest]

Joels,

 

Actually no, sometimes the harder the material the better it form taps.

 

I've formed Steels, Stainless Steels, Titanium, Hastalloys, so you should be fine.

 

HTH

[Toolfab]

Joel the diameter to LOC ratio is too great in this situation. You would be much better servered tapping this hole. Thread milling with more than likely a .156 diameter thread mill to that depth, you would certainly be bummin.

 

JM2C

 

[chris m]

+1 to Mr. Whitten

 

The OSG Hy-Pro NRT form taps are excellent and will give a nice result in mild steel, even though that is a pretty deep hole for a #10. I tap #8-32 holes in 1144 steel quite often about .640 deep using a TiN coated Hy-Pro NRT. The only problem with OSG is that sometimes their taps are a little short, if that's the case YMW makes excellent taps that are typically longer.

 

In your case I would use a 5.7mm (parabolic) drill to start and run that tap at 603RPM [rigid tap] with a minimum of .060 clearance under the tap.

 

This speed is a little conservative but it would get you going.

 

C

[Joels]

Thank you all for your input. i am going to ask the leaders about thread forming and i have some taps for steel that should work. I am going to use a Fadal VMC the only other process i was considering was tap pecking but i am not sire the Fadal will do it. I read in other threads that i have to add a Q to the G84.1 line to get peck tapping so i will try that today too.

[Harryman]

I personally don't think there is any benefit to pecking a form tap. Pound it in. Just make sure the hole size is correct. You need to use a different size than cut tapping.

[Tim Aydt Prototek Engineering]

Sometimes brushing a little moly-dee as opposed to a water soluble works wonders in this app.