Tapping Threads

[o_mccarroll]

My Autometer gauges came in about a week ago... I have no problem with any portion of the installation. I am just fine with wiring and mounting the gauges. My weakness is that I am inexperienced with tapping threads. I borrowed my dad's tap and die set last time I was home and I have been practicing on a piece of pipe to get a feel for it, but the results are just not convincing me that I am ready to drill into my beloved truck!



Anybody have any pointers or encouragement on this?

 

[JWhitcomb]

Can you tell us what size tap and where you want to drill?

 

[o_mccarroll]

1/8" NPT.



Pre-Turbo on the EGT.



I have no problem drilling or knowing where to drill, it's creating a clean thread that I am worried about.

 

[Bob Wagner]

OR if you have a fax number I will fax you a copy





FAX SENT

 

[cap-n-cray]

Practise

Get some aluminum and some steel. Drill five holes in each and tap them. You will be an expert if you don't break the tap. Practise on something less important than you Cummins.

 

[B.G. Smith]

Also you will find that the cast iron of the exhaust manifold will tap easier and the threads will be much better than in a steel pipe. Use a good tapping fluid. I use Tap-Ease. bg

 

['956Wheel]

Use anti-seize to lube the tap for 2 reasons, (1. GOOD CLEAN THREADS, 2. ) It will hold the chips. Start straight and you got it made. Remove the tap and check ,with the fitting, for correct depth.



Some will say ah bull$hit on the anti seize... 25+ years as a machinist I may know a little. Also, when drilling do not egg shape the hole.



Mike



CHECK DEPTH OF TAP OFTEN AS IT IS A TAPERED THREAD.

 

[Ron Bissett]

Tip on tap, Drill straight up and down with drill . To keep from egg shaping hole check for Run out (no waving of tip of bit) caused by worn chuck. When using tap short foward and back motion cut and clean take little cutting at a time slow no side pressure ,if some one talks to you while taping stop . Talk while holding tap without moving make next movement back with tap . start again check with fitting for fit. Do not forget you can drill out to larger size and use reducer plug . If you brake off tap a tap remover sometimes will work (parts store)looks like fingers . Taps are hard but brittle willnot take side pressure keep it straight . Lube and you will be ok. Hope this helps Ron in Louisville KY