Confusion Of Style Of Taps To Purchase

Swerdk

Swerdk

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Got a budget of $200 to purchase Taps. New to lathing and have been told that dies are not used nearly as often so just buy dies as needed.
There are 3 types of taps - bottoming; plug; and taper. Which type are the most commonly used on jobs? Want to do mostly model engine building and improvement construction on lathe. 12x36.
I see they are sold in sets but i assume a set for $30 is some cheep taps being one goes for $23. ( same brand too)

Tell me your favorites guys? Brands and types and catalog companies. Thanks


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I have several older hansen brand sets and even an older craftsman set. High Speed steel sets are more expensive than carbon steel and last and cut better. I have gun taps for small delicate work. Most of the bottom taps I have are rescued broken plug taps. Buy a nice set of taps and dies in the middle of your normal range of sizes you intend to work and pick up doubles as you find good deals at MSC and ENCO and keep a look out for a deal on a small quantity of left handed. They sure come in handy. No charge for my .02 cents.
 
Depends on what you are going to use them. The taper or starting tap is used for taping a hole for the first time. Bottom taps like the name states is to finishing tapping to the bottom of a blind hole. Plug taps are used for chasing or restoring threads. And then there is even more choices. Such as spiral point tap, spiral flute tabs, and thread forming taps.
 
So bottom taps cant be used to start holes?


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It's much more difficult. A bottoming tap only has a couple of tapered threads. A plug or taper tap is bettr suited for starting. And for through holes, you can't beat spiral tip taps.
 
If you are power tapping use three or two fluted taps. They have more metal than four flutes ones. Four fluted ones are for hand taping and could break if they get in a bind. They need to be backed out so the chips can be removed. Bottom taps should be done by hand so you know when it bottoms out. I usually drill the tap hole deeper so I don't need a bottom tap if the part allows it.
 
You have plenty of budget I just purchased 10 taps for $137, Guhring made in Germany Cobalt spiral point bottom taps. Two sets one set of 2 flute for aluminum/brass and one set of 3 flute for steel in these sizes 8-32, 10-24, 1/4-20, 5/16-18, 3/8-16. Purchased them on sale at MSC.



While these are "bottom taps" they have enough taper at the end to start a hole when tapping with a machine. I would also feel comfortable using these taps when hand tapping either with a tap wrench or chucked in a cordless drill IF the material was thin. I might think twice about trying to hand tap a deep hole with these by hand. You can absolutely get a tap started crooked and snap it off half way through a hole when hand tapping, don't ask me how I know this :cussing: I have standard bottom taps that are much more squared off that I would not attempt to start a hole with by any means.
 
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A bottom tap would be hard to start straight and would be gutting full depth from the start. Where as a starter tap each thread up goes a little deeper. A plug tap gets to depth in fewer threads. In softer material plug taps do fine. The taps Coolidge posted are spiral flute taps. That evacuate chips much better. They are for power taping, but work very good hand taping as well.
 
To add to what has been said, I suggest you do your shopping on ebay, buying only new stock. Prices typically range from cheaper to stupid cheap. Brands that work well for me are OSG, Titex, Ghuring and any of the quality US makers - PTD, Cleveland, Triumph, etc. Lower end are Irwin-Hanson, though they make decent taps and bottom end is stuff like Vermont American. If you are lucky you'll find a set that nobody notices, like my brand new $5.00 Titex cobalt drill/tap set from 6-32-1/4-20 ... sorry, had to gloat.

If you're doing model engine stuff then you'll probably be working on the smaller end of things. Good taps are necessary. If working with more malleable materials - aluminum and brass - try to use roll taps. They are stronger, produce no chips and make cleaner, more precise threads. They work in steel but are intended for softer materials.

When possible, use spiral point taps, AKA gun taps. They do not require you to break chips and back out - they push the chips ahead and therefore work best in through holes.

You can absolutely start a bottoming tap in a hole but it helps to do this with either a tap guide or leaving the work in the vise and starting the tap with the drilling spindle to get it going in straight. You need to use more pressure but you can do it. Naturally, the right way is to start with a taper or plug tap first but sometimes all you have is a bottom tap and I have made this work many times before.

Look up fits. All taps are ground to standards and the more precise the fit, the higher the cost.
 
Yes it can be confusing. Manufactures can’t get together and call the different tap designs with common names. Anyway, I like gun taps or maybe they call them spiral point. The tap pushes the chips ahead of the tap. The tap is much beefier, makes it kinda stronger than its other tap friends in the same size. And it can be power tapped with ease. Works well with through holes or holes with room for the chips to go. Or, the fast spiral taps. These taps are great if you want the chips pulled out of the hole when tapping. Can also power tap with these, but chip blockage could be a problem. I have some of those old hand taps somewhere??? Have not used that kind in decades…Good Luck, Dave.
 
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