power hand tap

What everyone said about using a screw gun or electric screwdriver. Works well, but be meticulous about blowing away chips and keeping things lubricated. Have plenty of new taps on hand and toss a tap the instant it seems to be getting dull. I know this will go against your grain, but it will be far cheaper in the long run.

Accu-Lube is one brand, Boelube is another. It does feel like waxy soap. It doesn't works as well as regular cutting oil, but doesn't make as big a mess either.

Thanks for that Ned, I've not seen those brands on my side of the pond however there are other "dry-lube" sticks. I've grab some and try it.

"N" sez: "Many modern cordless drills have an adjustable tension setting which lets the chuck slip at a certain point."

A non-issue because taps are usu. broken by leaning out of square with the hole

- it only seems like spindle torque did it.

Bob Swinney

Don't overlook rivet nuts

thanks Tim

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

I don't recall the brand, but I saw some stuff at a machine tool show that was in thin rods. The idea was that you pick the size that fits into a blind hole, stuff it in all the way and cut it off flush with the top. As you run that tap in, the lube is compressed, and forces the chips back out the flutes. They did a demo, and it seemed to work pretty well, but I suspect it depends a lot on the tap & material. I can't imagine it would work well with a gun tap.

Not really applicable for the through holes under discussion, but an interesting dodge in the tap lube department.

Doug White

With 8-32 or 10-32, I would use a gun tap in a drill motor (electric drill) with variable speed and easy reverse switching. If it tends to coast on for a while before stopping, I would make up a sliding tap holder which would disengage when I pulled the drill motor back.

Better would be a TapMatic tapping head with a bracket holding an anti-rotation bar, but that would be heavier and harder to maneuver

-- unless you have a way to get the electrical cabinet on a drill press, in which case the TapMatic head will be great.

And you might try the drill tap combinations so you don't have to keep swapping out the drill bit and the tap.

If you need the sheet to also make a good ground reference, I would go with steel or copper. If it is just for mounting rigidity, the aluminum (of sufficient thickness) should do.

Enjoy, DoN.

The DoAll wax is soft enough you can roll your own. But if you had to do many, the rods would be the bomb.

In Lautard's "Machinist's Third Bedside Reader" TMBR#3 he recommends wax threads for this and shows a design to create them by extrusion.