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- Apr 30, 2015
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- 12,604
You forgot the excellent Widia/GTD taps- the gold standard, for me anyhow
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TAP PROBLEM
- Thread starter riversidedan
- Start date
- Joined
- Dec 21, 2018
- Messages
- 2,225
Chances are they are less than ideal taps if they are sold in hardware or big box stores. Quality taps are "too" expensive for the people that go to the hardware/big box stores. The cheap taps get really expensive when you break them in a hole. If you can't use a drill press or mill, just drill a block of hardwood by hand or better on a drill press and use it to keep the drill & tap at 90 degrees. Center punch so the drill doesn't wonder off the the bar while you aren't looking. The tap you are trying to use doesn't have enough starting threads.
- Joined
- Jan 6, 2017
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- 1,252
The reason everyone keeps telling you to get HSS taps and skip that carbon steel stuff is because they've learned, from experience.
Most everyone here has, at some point, needed to tap a bunch of holes at some point in their careers. Most tried carbon steel taps, learned the lesson, and moved on.
This HSS thing they keep mentioning, is the most important aspect. Not the brand so much.
You have, here, for free, the collective experience of a whole lot of people, who have been exactly where you are, found the solution, and are now offering the benefit of that costly experience.
Get a HSS tap. You'll soon find yourself on here responding to a similar thread, telling others the same thing.
But yes, the Irwin tap will probably be fine for aluminum. Personally, I like my taps to be good for steel too. I've used Irwin taps, in both aluminum and steel. Got a few good uses out of it. My HSS taps last year's, and make tapping holes an easy thing.
When I first started out, using hardware store taps made the experience suck. I was always worried about breaking taps, and many times did. Sometimes, even in aluminum.
With HSS, I can power tap several hundred holes with my mill and never have an issue.
A couple years ago I did a run of about a thousand 6061-t6 14mm, 17mm and 5/8" speed handles to fit import, and Glacern 5" milling vises. I set up a work stop on my PM935 and each one got a 5/16-18 hole. All done with the same 10$ hss tap. It took less than 5 seconds per hole. I still use that same tap.
One of my customers at the time was Jesse James Gunsmithing LTD.
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That is not quite accurate. In general, the tap hole should vary with the type of material being tapped. The thread depth can vary from as low as 25% to a maximum of something a bit less than 100%. Typically, the harder the material, the lower the thread depth. Thread depths less than 50% or more than 75% are usually only for very special situations. A 5/16 drill will produce about a 75% thread depth, which is good for plastics, brass, aluminum, etc. It is a little bit small for hard materials such as mild steel, stainless steel, etc. It is probably OK for cast iron, although one might consider going to perhaps about 0.32" or so - about a P drill - if one is having trouble in cast iron.
Amen. Most of us are concerned about cost, and high carbon steel is almost always less expensive up front than HSS. Believe me, I can sympathize. In the long run, however, HSS is going to wind up less expensive, because it will cut faster and cleaner and usually last much longer. As others have mentioned, the less expensive taps will work well enough if all you are machining is brass, aluminum, plastic, etc. Otherwise, HSS taps are pretty much well worth the cost. The only exceptions, perhaps, might be a specialty tap, which is only probbably going to be used once or twice in a blue moon, or a sacrifice tap, which one knows will be destroyed by the tapping process, or a bottom tap.
Personally, rather than buying bottom taps, I would recommend buying HSS plug taps, and along side them buy cheaper plug taps and grinding the tips off. After making the initial thread with the HSS tap, the modified carbon steel tap can be used to finish out the hole. The bottom tap will only be cutting three or four threads, in each hole, and when it gets dull, it can be sharpened several times by grinding back the tip.
When hand tapping, if practical, I like to counter-bore the hole a bit. This not only helps a lot in getting the thread started, it also helps make sure the tap is straight. I also heartily recommend a tap guide. They are inexpensive, and really help a lot with preventing tap breakage and with getting better quality threads.
- Joined
- Apr 14, 2014
- Messages
- 3,587
Sorry about that. I knew I would miss at least 1 quality brand. Rather than work from memory I should have taken a few steps into the shop and looked in the tap cabinets. I probably have well over a hundred WIDA taps in different sizes and configurations.
I must admit I do have a few carbon steel taps in the mix. Right now I think it's limited to 3. I can't even remember the job I bought them for, but it was a 1 off and probably close to 20 years ago. They're 9/16-20 left hand thread. I searched high and low to find them, and finally found a set (Taper, Plug, & Bottom) at McMaster. At the time they cost around $40.00 for the set. McMaster doesn't even carry that size in carbon steel anymore. The only 9/16-20 left hand tap set the currently have in the lineup is HSS, and it's almost $220.00 for the set.
In most cases I don't believe carbon steel taps are cost effective. In the case of the 3/8-16 size eBay has new in the package Irwin carbon steel ones with an asking prices from $7.95 to $9.95 each. eBay also has new HSS hand taps by Accupro (7.99 ea.), WIDA ($8.00 ea.), YG-1 ($5.09 ea.). These are prices for single units. There are also a number of listings for multiples. In the case of multiples the unit price for HSS goes as low as $5.00 per unit for name brands.
We have a large assortment of found taps and the usability varies greatly.
Was working a 1 inch steel plate doing 3/8 16 and first set was easy, grabbed wrong drill so a bit over sized but good enough.
Was drilling then tapping with mill.
Next day had correct drill and mill snapped the tap.
Next tap was hard to use so selected a 2 flute hss and it went in like butter.
Hardware store stuff is chasers.
Sent from my SAMSUNG-SM-G930A using Tapatalk
Was working a 1 inch steel plate doing 3/8 16 and first set was easy, grabbed wrong drill so a bit over sized but good enough.
Was drilling then tapping with mill.
Next day had correct drill and mill snapped the tap.
Next tap was hard to use so selected a 2 flute hss and it went in like butter.
Hardware store stuff is chasers.
Sent from my SAMSUNG-SM-G930A using Tapatalk
