Tap guide needed

I've seen machinists use a small block with a bunch of holes in it where the tap would be inserted to guarantee that the tap threads straight into the hole to be threaded. I could simply drill a clearance hold in some scrap metal, but if I wanted to machine such a guide,there must be some good ideas out there. It could be a rectangular solid with a row of holes different diameters, it could be a disk, etc. What do most people use?

I know of other techniques using the drill press chuck, a spring- loaded tap guide, etc, but in this application, I would like a simple guide.

Jim

Reply to
hoseman
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A narrow long object with a series of properly sized holes would be most useful, although there are likely instances where almost nothing would work. The narrow one would allow for tapping near shoulders, but might not allow getting into corners. I'd avoid a large round object, which would likely be very restrictive except for flat objects. Regardless of configuration, you're bound to encounter projects where the guide will get in the way.

If you make a guide, make sure you mic the taps to determine the size your holes should be. They (taps) are always oversized. For example, a random sampling of 1/4" taps will reveal diameters from .253" to .256" on the major diameter. Even the body of the taps will be oversized, so you want to make sure it will clear the holes in your guide for the deep holes you are likely to encounter.

Harold

Reply to
Harold and Susan Vordos

Remember that you need the hole drilled vertical if you are going to use a guide to make sure the tap is vertical.

I have two sorts of drill/tap guides. One in a bit of scrap 1 by 4 that I drill the hole on a drill press so it is vertical. It is quick to make and easy to dispose of.

The other are some drill guides I got a Boeing Surplus. They are plastic about 1.5 inch in diameter and about the same height. They are threaded for a half inch bolt. Bolts with different size holes can be screwed in to them.

Dan

Reply to
dcaster

Thanks for the info, it was what I was looking for. - Not to make it too big, can't get close to edges. The idea of using inserts, I hadn't thought of. I remember years ago on jigs making hardened drill guides. Thanks for all the tips -

Jim

Reply to
hoseman

hoseman wrote in news: snipped-for-privacy@4ax.com:

Another option would be to make a small hand tapper like the one Flexbar makes:

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It's a little more than half way down the page. It's also handy for hand reaming holes. You can also see what their tapping block looks like there as well.

Reply to
D Murphy

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This one works great, and for the price, it's a bargain.

Doug White

Reply to
Doug White

Just a tip you may have missed hearing about Doug:

If you enclose a "long" URL between "angle brackets" like this:

It'll be much easier for folks to click on it and get to where you are directing them.

Without the angle brackets long URLs which get displayed on more than one line won't get you there with a simple click. You have to use copy and paste to piece them back together again in your browser's affress bar.

Do it like this:

Course you could also use tinyurl.com to "shrink" it, but I find it faster to just stick the angle brackets on both ends, and users may be able to get an idea of where they're heading when they click on it.

Jeff

Reply to
Jeff Wisnia

Thanks for the tip. It doesn't work with all newsreaders, however. I use NewsXpress, and I still have to cut & past long URLs, brackets or not.

Doug

Reply to
Doug White

This is a perennial apprentice project. Most are something like you mention, just a block with tap-sized holes in it, pattern and variety to suit your preferences. You probably could find any number of designs in high school metal shop texts.

I've got one I purchased from Brownell's long ago, it's a round puck with interchangeable bushings. The bottom has a V cut in it so the user can easily line it up on round stock, like a barrel. It's still for sale, but I think the current price is rather out of sight.

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You could bore the jig's hole so you could use standard die bushings that can be had from the usual industrial hardware suppliers. I use mine a lot for the smaller taps, it keeps tap breakage down to virtually nothing. One thing I think I'd rig up is some sort of clamp so it could be held to a workpiece. Kind of hard juggling jig, drill and workpiece some days. These days, one or more rare-earth tooling magnets might work, if you could find some way to keep the chips from sticking permanently and you work mostly with steel.

Stan

Reply to
stans4

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