Inside threading, can you recommend some tooling?

WobblyHand

WobblyHand

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I'd like to make a canister, kind of like a film canister (remember them?) that's a little longer. It would be nice to have inside threads on the canister, with external threads on the cap. Can someone recommend some tooling for inside threading? I've done some looking around and find it pretty confusing. Is there LH tooling available? My chucks are bolted on so I don't have to worry about them spinning off. Kind of anxious to single point them blind (normal way), that's why I am asking about LH tools. Only have a mini-lathe, so big bars need not apply. The largest possible bar I could use is 1/2" and I'm not sure I can guarantee getting a 1/2" bar to center. I have seen some bars with carbide or even HSS inserts, but am unsure what would be "good enough".

I have read about inside threading on HM, but sadly there are few if any pictures of setup. I find the visuals very helpful.
 
What size? What material? I'm assuming that you will want thin walls, so I would do it with a very sharp HSS tool set in a boring bar. I would also do it blind. This is a skill that you will need if you're using a lathe, so practice it now and become proficient at it.
 
If you are flank feeding angle the compound 29.5* in the opposite direction from what you use for external threading. If plunge feeding it makes no difference how the compound is set.

I am with SKL001 on the tooling, a boring bar with a 60* tool bit. I prefer this over carbide insert tools.

If you are determined to use carbide check out Banggood for internal threading bars.

Micro 100 sells internal threading tools in HSS.
 
Threading with the tool upside down, on the inside of the back is less stressful, the tool comes out of the work as it cuts, rather than having to stop before it crashes. With the spindle turning toward you, (conventional) you cut the same direction as when threading outside.

Small bore. Start with a 3/8" HSS tool blank and remove (slowly) all the stuff that isn't a cutting tool. You'll have to be exceedingly careful to leave the threading tool on the end, but it's worth it. You won't be leaving more than 1/2" of thread, so get a narrow grinding wheel, or spend a lot of time with a 3/4" wheel.

I have made a threading tool from a No 0 center drill, captured in a piece of drill rod for ID work, too.

It's all good experience.
 
Bokum makes HSS threading tools with 3/8 integral shank, form relieved, grind only on top, lasts for many years with normal use, not sure if they make a left hand tool.
 
Wobbly: When you say LH threading do you mean to cut a left-handed thread or do you mean something else?
-M
 
Last edited:
markba633csi said:
Wobbly: When you say LH threading do you mean to cut a left-handed thread or do you mean something else?
-M
Click to expand...
Not a left hand thread. Sorry, I meant to use a LH tool and thread outwards.

I'd try a HSS tool "normal" in. No way for a Micro 100 solid threading tool in normal mode. I would need a ton of practice with a HSS tool first before using a Micro 100 tool. The Micro 100 would have a life of less than 5 minutes in my hands! (4 minutes and 30 seconds of trying to screw up my courage to try and 30 seconds of use!) They snap real easy if you bump the bottom, had a Micro 100 solid carbide boring tool that I used for quite a bit, then a moment of wandering attention and pop! $40 evaporated in a millisecond. Need something more forgiving in the beginning.
 
benmychree said:
Bokum makes HSS threading tools with 3/8 integral shank, form relieved, grind only on top, lasts for many years with normal use, not sure if they make a left hand tool.
Click to expand...
I will check that out.
 
Ok, for threading outwards, RH (conventional thread) two ways:
1) Spindle reversed, tool down, cut inside of bore closest to you ("LH style tool")
2) Spindle reversed, tool up, cut inside of bore away from you ("RH style tool")
I think the second one is easier, better visibility
-M
 
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