OSG HY-PRO NRT

[RACINGCONVERTERS]

Hi, I finally have taken everyones advice here and purchased some roll form taps. The only problem is I have never used them and do not know what kind of speeds and feeds to run. Can any of you point me in the right direction?

 

Okuma mcv-4020, Rigid tap, Valenite tapping holder, 5/16-24 thread, 7.45mm drill, rapid to .1 above the hole.

 

Thank you all for your help.

[jeff]

As far as I know you run them the same as regular taps.

But I don't have that much experience with form taps.

[T_MALENA]

What matl are you cutting?

we run close to regular cutting taps. Also start with OSG's feeds & speeds, then adjust to your needs. Just be aware when forming in a blind hole, use blind hole forming taps! They are designed to allow coolant/air to escape a blind hole!

 

 

try this:

 

(steel)

G0G90X0Y0S1000M3

G56Z.2H1

G95

G84X0Z-.60R.2 F=1/24

[chris m]

What is the material? The Hy-Pro is good for Austenitic S/S, aluminum, mild steel, etc. If you are tapping hard stuff you are better off with the ExoTap NRT. Typically roll form spindle speed is 170 - 200% of the speed for cutting threads in the same hole. I would consider an M for a tap drill, a couple of thou bigger than your 7.45.

 

C

[RACINGCONVERTERS]

The material is 7075-T6 and maybe 1018 later. It is a thru hole about .525 deep. I was told to run 50-90 sfm which seems way fast.

Another question is that if I speed the tap up do I need to raise the start point so that the spindle reaches full speed before entering the hole.

[chris m]

I would say 50 SFM in 7075 would be no problem [i run 30+ in mild steels with no sweat]; 612 RPM with 25.4 IPM should be no real issue for that machine. You should not need to start any higher as the machine shouldn't move if it isn't in synch, BUT, another .100 or .150 ain't gonna take long at 25 IPM...

 

C

[RACINGCONVERTERS]

Thank alot Chris you have been a big help.

[RACINGCONVERTERS]

Chris,

 

My boss is not liking how loose the bolt feels going into the hole on 2b hole is there any way Ican get the hole to feel tighter.

[chris m]

Didn't realize the 'feel' test was part of the inspection procedure...if the Go goes and the NoGo doesn't and the minor diameter is in spec then the thread is good, right?

 

That being said, there are a couple of things you can do:

 

1) run a slightly smaller hole [which will lead to premature, or immediate, tap breakage

 

2) get a smaller "H" number tap; run and H6 instead of an H8, etc.

 

The "feel" of the formed thread can be an issue for people, so you can play around with it a little, but if the gages say its good, its good. You can always do a "torque out" test on the threads to "prove" they're OK; put a screw in the formed hole and torque it until the thread strips or the head breaks off the screw, then repeat with the cut thread, this should quiet any of the squeamish.

 

C