A question, from my own ignorance

[Downwindtracker2]

I had used a ratcheting tap handle for 20 some years at work. You just have to twist your wrist. Mine is a German made Mastercraft. Yes Canadian Tire does sell good stuff. I bought one for home, it was Chinese. The first hole had it tossed into the scrap iron bin.. I bought another from Canadian Tire.

Small taps are fragile , but your 5/16" and 3/8" are done in a lot of shops with variable speed drill motors, relying on chuck slippage, for production. I've done that a few times myself.

If a tap gets tough to use, it has gotten dull. Toss it before it snaps on you in a hole. They fatigue.

 

[Superburban]

I have always done the 1/2 turn, and then back 1/4.

But reading this got me thinking. With reamers and drills, they say not to turn them backwards, or you can dull them. But taps are ok to back up. Maybe we are doing more harm then good. I have to mull that over.

Bill. Do not skimp on the Oxygen. less is worse then more. Get one of those cheap finger devices, and test yourself often. Did you also get a CPAP? If so, please learn to use it. I need yo to stay around, and keep providing the good wisdom.

I was shocked to learn that my Blood Oxygen levels dipped down to 50% when sleeping. My biggest issue with using the CPAP, was the crazy nose mask the VA gave me at first. When I got a full fave mask with a chin cup, it was so much easier to use. Now I use it every night, well over 10 years now.

 

[hman]

I usually associate spiral flute and spiral point taps with machine tapping, not hand tapping in the field.

Just about all my tapping is by hand, and just about all my taps are spiral point. Even in blind holes, they're the cat's pajamas! (I usually just pilot drill a bit deeper if it's a blind hole and leave the chips in place, unless it's something I'll need to repeatedly unscrew.)

 

[rabler]

I have a large collection of those T handled tap wrench. All of the decent ones are from a toolchest I got from my grandfather when he passed away. A couple of the larger ones ratchet, they have three positions: in, lock, and out. So you can use them however suits your needs. If I happen to be using a small tap or cheap tap or tapping hard material, I go in/out. I found you can feel, to some extent, the spring in the twist of the taps as they get stressed, so I'll use that to judge when to switch from straight twisting to in/out. No, I do not claim to be an expert and have certainly goofed 'em up (broken taps).

 

[Bi11Hudson]

Bill. Do not skimp on the Oxygen. less is worse then more. Get one of those cheap finger devices, and test yourself often. Did you also get a CPAP? If so, please learn to use it. I need yo to stay around, and keep providing the good wisdom.

I was shocked to learn that my Blood Oxygen levels dipped down to 50% when sleeping. My biggest issue with using the CPAP, was the crazy nose mask the VA gave me at first. When I got a full fave mask with a chin cup, it was so much easier to use. Now I use it every night, well over 10 years now.

Thanks for the concern. This is something I have been dealing with since 2005. That's why the Mullein mixed in so heavy in my smokes. I have (VA) an "oxygen concentrator" that puts out near 100% O2. I won't go into details here, not the place. But when I got burned in 2005 is when I started smoking again, with a 50% mullein mix. It smells like white sage, almost like pot. I've sat in a coffee shop where cops hang out and stirred them up a little. I use the tube that slips in my nose and hangs from my ears when I sleep. I try to use free air in warm weather, but as the air cools and I close the windows, the inside gets a little stuffy. I am aware of the dangers of high oxygen so don't smoke when the machine is charged or running.

.

 

[davidpbest]

I usually associate spiral flute and spiral point taps with machine tapping, not hand tapping in the field.

Spiral point taps are more robust and less prone to breakage than a conventional plug or gun tap. This is because the cross section of the spiral point tap has more meat. The opposite is true of spiral flute taps - their material cross section is less than a conventional tap and really only a good choice for machine tapping applications where there is precise control of tap alignment to the hole.

Material and tapping fluid are also important factors. The most challenging situations I have found are deep blind holes in 316 stainless at diameters of 4mm (#12) and less - in this situation constant feed is required on both pilot hole drilling and tapping to prevent work-hardening, and tapping fluid is absolutely necessary. The worst approach with stainless is to drive forward, then back to break the chip, since it work-hardens the material which substantially increases the risk of tap breakage.

 

[vtcnc]

I had used a ratcheting tap handle for 20 some years at work. You just have to twist your wrist. Mine is a German made Mastercraft. Yes Canadian Tire does sell good stuff. I bought one for home, it was Chinese. The first hole had it tossed into the scrap iron bin.. I bought another from Canadian Tire.

Small taps are fragile , but your 5/16" and 3/8" are done in a lot of shops with variable speed drill motors, relying on chuck slippage, for production. I've done that a few times myself.

If a tap gets tough to use, it has gotten dull. Toss it before it snaps on you in a hole. They fatigue.

Those above are the two key points in avoiding breakage during “hand tapping” when wanting to do it faster with a hand drill or using small taps.

Low torque on the clutch is key. And small taps can be run through back panels easily on lower torque settings and liberally dipping the tap in cutting fluid. In a past life I was the manufacturing engineer for a panel shop for an injection molding machine company. We ran a ton of small metric taps through hundreds of holes per cabinet panels with Bosch cordless drills.

As mentioned you need to get a feel for when it is getting dull and quickly cut bait.


Sent from my iPhone using Tapatalk

 

[jwmay]

Thanks for asking the question, because I'd never given it a passing thought. Those ratcheting tap handles are the answer to the tight quarters issue. I feel silly for not realizing it now.
When I run a tap by hand, I do just like you say, and just like my instructor taught me. But at work, I usually power tap with a cordless drill unless I'm below a #8 cap screw. If it's thin metal, I'll power tap to the smallest size I deal with, which is probably M4. But nothing gets power tapped on the mill smaller than 1/4". I can feel the drill, but the mill will snap a tap with such ease and lack of indication that I don't risk it. My reaction time is also better with the drill. Finally, the only taps I've ever broken were in a jacobs chuck on the mill, or by hand tapping. I'm pretty sure I've never killed one with a drill.

 

[woodchucker]

I didn't notice anyone mention a 2 flute tap in tougher material to avoid breaking taps.
I have found that they are tougher in tough material, and the flutes have more room for chips..

just adding my 2 cents..

 

[Bi11Hudson]

Thanks for the responses, I had thought there might be some esoteric tool that they were suitable for. Close quarters are the reasoning though. I have turned many a tap with a (6") crescent wrench in tight quarters. Doing work in the field leads to many unusual methods. Sometimes it's a matter of what's on hand versus 3 hours to return to the shop for a proper tool.

Much (most) of my tapping is for the smaller (tiny) sizes. Nr 6-32 and smaller, with a smattering of 8-32 and 10-24 and 32. 1/4-20 is large to me. For my smaller sizes, 3/0 up to about 2-56, I use a pin vise as my tap wrench. Not so much to turn with my fingers as to have the "slip" available if things get too tight. I use a pin vise by Xacto, although there are numerous makers. The changable collets make fitting various sizes easy. The pin vises make feel for torque much easier. I have some "improperly finished" holes but few broken taps in the small sizes. ZAMAK is the only real problem, too "sticky". I use threading fluid, several brands. And drilling oversize. And several other "tricks". But ZAMAK is tough.

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