3/4-16 LH Form Tap

[sknies]

Hello,

I am tapping 1018 steel and am in need of a 3/4-16 LH tap for a lathe job I have coming up. I am going to tap 2" deep, but the first inch is a counterbore, so only an inch of threads.

I have been using a 3/4-16 Guhring RH Coolant thru Form tap for awhile now with great success. They do not make a LH Form tap and a special has a long lead time.

Wondering if anyone knows of a company that has LH Form taps.
Also open to what has worked for other people as far as a regular LH tap.

ID thread bars have not worked well in this application, tapping has been better.

Thanks in advance.

 

[JackOfNoTrades]

I haven't found anyone who makes them standard. You say an ID bar doesn't work well, but did you try a carbide shank bar or steel? Also your speed and # of passes are critical for getting a good finish. You would have to use the tool manufacturer recommendations to get that info. People tend to run threading tools too slow. 1018 is going to want quite a bit of speed and larger DOC. Light DOC leaves a bad finish.

 

[Mtndew]

Try Regal, they can do quick turnaround on custom taps.
https://www.regalcuttingtools.com/products/threading-taps/met-flo-forming-taps

 

[Ox]

Jarvis Cutting Tools has made special chamfer form taps for me in the past. (like 1.5 rev start chamfer)
Whether they will doo a LH thread form or not - I wouldn't know.

However, I pinged them for a new project a cpl days ago, and not gotten a re: yet.
I have not bought from them in many years by now tho.

But I will say that I recently had MUCH better luck with some NOS Jarvis form taps in 304SS than OSG by far.


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Think Snow Eh!
Ox

 

[Ox]

I just got off the horn with Engineering at Jarvis, and while we were there, I asked him about your app, and he said "Absolutely".

Jarvis Cutting Tools @ 800-258-7162


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Think Snow Eh!
Ox

 

[Zeuserdoo]

Does your lathe have live tooling, if so you could threadmill it.

Or you could give that id thread bar another try by threading from the bottom up since it's a left hand thread, it's always nice to pull chips out of the bore if you can.

 

[JMC]

Almost defiantly going to be a custom. I have had great luck with Jarvis and North American Tool for custom form taps. NAT had a better lead time if memory serves.

 

[Ox]

NAT has made custom specials for you?

I thought that they purty much stuck with the standard specials that they had in their catalog?


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Think Snow Eh!
Ox

 

[TeachMePlease]

I'd check with Emuge and see if a 3/4-16 "special" might be made rather quickly, since they go up to 5/8-18 as a standard. REK. B Steel - UNC/UNF- GLT-1 | Emuge Corporation

 

[Ox]

.... "form" .....


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Think Snow Eh!
Ox

 

[TeachMePlease]

.... "form" .....


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Think Snow Eh!
Ox

Dammit, I was on a page with LH FORM taps... And then I wasn't.

 

[SeymourDumore]

NAT has made custom specials for you?

I thought that they purty much stuck with the standard specials that they had in their catalog?


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Think Snow Eh!
Ox

Ox, I can absolutely tell you that NAT will not only make Blueprint-Special taps, but they do it in less than 72 hours!!

 

[JMC]

NAT has made custom specials for you?

I thought that they purty much stuck with the standard specials that they had in their catalog?


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Think Snow Eh!
Ox

Just recently had them make 1/2-13 LH Form taps. Their turn around was excellent.