Drive screws

[mklotz]

If you examine your machine tools closely you may notice that the nameplates and information plates seem to be attached to the machine with what look like round-headed rivets. These are not rivets but rather a type of fastener called a "drive screw". They look somewhat like a rivet with very fast screw threads...



In use a hole is drilled into the nameplate and a matching hole is made in the machine to which the plate will be attached. The drive screw is threaded through the plate and driven (hence the name) into the hole to secure the plate.

If you want to restore or repaint the machine, a neat job may require removal of the plates. Ideally the drive screws should be removed carefully so the plate is not damaged but how to do that?

In very rare instances the hole is a through hole and, even more rarely, one can access the open end of the hole. In this case, a pin punch can be used to drive the screw out from the back side.

If the screw was not seated fully, it may be possible to get a thin screwdriver blade under it and, bit by bit, lever it up far enough to grab the head with lock jaw pliers and "unscrew" it from the hole. If you try this, put a pad under the screwdriver so it doesn't mar the plate. Often these plates are made of brass or aluminum, both soft metals, and can deform and dent easily.

If the screw is fully seated, the screwdriver pry may be a non-starter. In this case, use a thin saw blade or cutoff disk in a Dremel or Foredom tool to carefully put a slot in the head of the drive screw. Unscrew the screw far enough to grasp it firmly with lock jaw pliers and unscrew.

It should be obvious that these fasteners, once removed, are not reusable. Suppliers like MSC and McMaster-Carr carry them in a variety of sizes. Alternatively, you can thread the holes in the machine and use small machine screws to remount the plates.

[NortonDommi]

When I was working in a fuel shop we had to remove the name plates before dumping the bodies and assorted bits in a Paragon tank for cleaning. I found a pair of those nail puller pliers cabinet makers use with a circular depression ground in the underside of the jaws with a Dremel so the jaws had positive location and a wedge action from two directions plus a twist would lift the pin. Important to wind them out if you want to reuse the hole. For the unwary the pins can be Left or Right handed. Easy to tell once it starts to lift.

[Metalmuncher]

When I was working in a fuel shop we had to remove the name plates before dumping the bodies and assorted bits in a Paragon tank for cleaning. I found a pair of those nail puller pliers cabinet makers use with a circular depression ground in the underside of the jaws with a Dremel so the jaws had positive location and a wedge action from two directions plus a twist would lift the pin. Important to wind them out if you want to reuse the hole. For the unwary the pins can be Left or Right handed. Easy to tell once it starts to lift.

I don't think I've ever seen those 3 words used in a forum post, until today. Wonder if the NSA is listening. That might grab their attention.

Seriously, thank you mklotz for this interesting bit of info. There have been times when I wondered about removing such "apparent rivets" but was afraid to do so would ruin the plaque or label being held. Nice to know they can be bought and replaced.

[Paul Jones]

Marv,
I had the best luck in removing the "drive screw" from the plates by applying a lot of forward pressure with a medium size lineman pliers while pinching very slight flats on the edges of the "drive screw" caps. After twisting slighting on the new flats and repeating the process several times, I have been able to back the "drive screw" out with the lineman pliers. The flat nose of the lineman pliers are made of very hard steel and can overcome the harden "drive screw" caps and deform the cap edges just enough to cause flats that aid in eventually twisting the screws out without marring the name plates. It takes some practice to do this right but it works very well.
Regards, Paul

[Metalmuncher]

Looks like they are listed under other names as well. McMaster Carr calls them Screw Nails. MSC Direct uses the rather misleading name "Sheet Metal Screw" for these.

They are available from these suppliers in either steel or stainless steel. I was surprised to find them in lengths up through 3/4"! I'll bet those could prove to be difficult to remove. Maybe for the larger ones, drill a hole in the center and use an EZ-Out?

[NortonDommi]

I've locked the doors. Dumping the bodies refers to the Diesel injection pumps, injectors etc. Pumps were totally disassembled and stripped to bare metal before reassembling with new parts, gaskets etc. They were then run and set on test bench finally painted in correct colour for whatever they were for and at the very last the I.D. plate/s put back on or a new one if pump had been reconfigured.

[mklotz]

Maybe for the larger ones, drill a hole in the center and use an EZ-Out?

I don't think I would want to try an EZ-Out. I would fear that it would expand the drive screw and wedge it even more firmly into the hole in which it's placed.

[Metalmuncher]

I don't think I would want to try an EZ-Out. I would fear that it would expand the drive screw and wedge it even more firmly into the hole in which it's placed.

Hmm. Well, I wonder how "deep" the head is on the larger sizes? The 3/4 inch length ones were the diameter of a #14 screw, which is pretty big. Maybe on those a hole drilled into just the head itself could support the use of an EZ-Out. Although the drive screws I found, above, are steel, I think on machines such as SIEG builds in China, they are either aluminum or some other soft alloy. I've drilled out a few, in the same manner one would remove a Pop-Rivet, and they were pretty soft.

[olderdan]

I have encountered a lot of these Drive Screws in small sizes usually in alloy castings and have found that heating the casting with a hot air gun makes removal of them a lot easier, then sliding two stanley knife blades under the name plate will often lift them. On one occasion all methods failed and some very precise drilling enabled the plate to be removed. New holes were then drilled just offset from the original.

[12bolts]

I have had pretty good success with using a very sharp diamond point chisel and tapping them out by working counterclockwise at them.