Help With Tap Selection

I have a prototype job that needs a few hundred drilled and tapped 10-24 blind holes. Most will be in 1018 steel with about 50 being in 6061 aluminum. I need to purchase some taps for the job. Recently I started using YG1 spiral flute bottoming taps for other jobs so I thought I'd give them a try for this one.

I don't use a lot of 10-24's so I thought I'd buy a box of "multi purpose" taps for this job and future use. Y.G-1 offers a couple that interested me.

One is:

YG-1 Part # F4323
10-24 H3 3 Spiral Flutes Bottoming Tap HSS-V Steam Oxide for Multi-Purpose
45Deg Helix, Right Hand Spiral, ANSI SHANK CNC Style Tap

The second is:

YG-1 Part # C2323
10-24 H3 3 Spiral Flutes Bottoming Standard Tap HSSE-V3 Steam Oxide for Multi-Purpose
45Deg Helix, Right Hand Spiral, ANSI SHANK Non-CNC Style Tap

While both are listed as "multi purpose" they are both "recommended" for mild steels and aluminum castings in their performance charts. Pure aluminum and aluminum alloys are not on the recommended list. I'm not sure what the difference would be between tapping an aluminum alloy casting and an aluminum bar.

I would like to know if anyone has had experience with these or similar taps, and if you think they would be appropriate for the job at hand.

What machine? If CNC, rigid tapping? How well can you hold your drill size? If you are good on hole size, take a look at form tapping.

Regards.

Mike

The work will be done on a Bridgeport Series 1 manual mill. To this point I don't have any thread forming taps, or some of the drill sizes necessary to use them. For this job I would prefer to stick with standard thread cutting taps.

I've never used YG-1, but I have had excellent results with OSG. Their A brand taps work well on just about everything from 6061 alu to 4140 prehard.

Prototype job ... any chance you can switch to the much easier #10-32 thread size?

Red James said:

Prototype job ... any chance you can switch to the much easier #10-32 thread size?

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Quite possibly. I have no idea why 10-24 was speced. I don't see anything sacred about that size.

If you can drill holes a bit deeper you don't need bottoming tap.

10-24 is the standard coarse thread and that is probably why it was called for. In most screw and bolt sizes, the coarse thread version if far more common than the fine thread. But in the #10 size, the 10-32, fine thread is probably just as popular as the coarse thread and just possibly a bit more popular. It is widely used in electronics, for one thing. So 10-32 is far more common than a 4-48, for instance.

There is nothing sacred about any thread size.

As for the original question, if you are going to use a tap that cuts the thread, please give some thought to where the chips will wind up. It is a blind hole so it may need to be deep enough to easily hold whatever percentage of the chips that stay in that hole. I like the thread forming tap idea if that will work for you.

Whatever you use, do use a good tapping fluid.

projectnut said:

Quite possibly. I have no idea why 10-24 was speced. I don't see anything sacred about that size.

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McMaster is currently selling Widia taps. I was having trouble tapping a 3/8-16 hole so I ordered a new tap. I couldn't believe how much easier it was to turn (by hand). Anyway, that's what I order now.

It isn't just what manufacturer, but with Enco gone and MSC/Travers ridiculous pricing, it's also where to buy them.