Machine plates fixing

HI, Does anyone know the correct term for the rivet headed, knock in fixings used to hold the ident and data plates on machines.

And, where I can get them from.

Regards. Steve Harris

Drive Screw or hammer drive screw

Edited By JasonB on 05/01/2023 20:46:25

I call them something rather different when I'm trying to remove them...

Suggest you look on page 15 of the 50 page catalogue of Automation Components . They are on 0333 207 4498 or automation components.co.uk.

i don't know of any tidy way to remove them without mashing up the plate below them. Very, very carefully grind the head off and remove the plate undamaged, but then you are left with nothing much to grip to try to pull out the remainder of the drive screw. And of course you can't drill them out, being hardened.

Trying to unscrew them with vice grips never seems to work. Can't get a good grip on the rounded head. So it's down to prying them out and that always mashes up the aluminum or brass plate and looks awful when you put it back.

There has to be a better way but I can't think of one. Anyone got any better ideas?

How about a small "Dremel" cutting disc to cut a slot in the domed head for a screwdriver? A small washer around the head might help protect the ID plate. Just a thought.

After one dire attempt to remove these, it became obvious to me it wasn't easy, or practical. They are used essentially as permananet fixing with speed of initial assembly in mind.

What I did subsequently was to grind of the heads with a dremmel, then it depends what you want to do next - If replacing it after a bit of TLC, grind the remaining part of the fittings flush, clean the surface and use a modern adhesive / epoxy of your choice to put it in place. Add 'dummy' rivet heads if so desired. Modern materials will hold in virtually any conditions of heat / vibration when used on such a relatively lareg surface.

The method I described has proved perfectly sound after about 8 years or so since I did it.

regards Mike

I have used a slotted wood chisel (under the label), and damage still seems unavoidable. To extract these quick thread drive pins, they need pulled out along the thread orientation.

I haven’t tried this, and have no intention of doing so, but I suggest using a Dremel or similar to cut slots per the attached. Anyone skilled in micro-surgery should find this easy. Then use strong end cutters to grip, rotate and pull. You may need to modify suitable end cutters by grinding them flat across the face so as that the gripping/cutting edge is outermost.

I've had good results removing them with pliers like this, which are ground for enhanced grip on a screw head. I've got a set of three sizes and the smallest size is perfect for griping these pesky fasteners and twisting them out without damaging anything.

I do what Bo'Sun advised above, that is use a dremel to cut a screwdriver slot in the head and simply screw them out with a normal screwdriver.

The last ones I did were on the engine number plate on my Morris Minor, prior to having the block faced.

Phil

When I was still working I used to buy them under the "Taptite" brand name.

Thanks for the suggestions guys. Some very good ideas there. I had not though of dremelling a slot and trying to unscrew them, always assumed the long lead on the sprirals would not lend itself to that so will give it a try next time. I like Ifoggy's specialist pliers too. Must try to find some on the net. They look very handy indeed.

Would be very handy for removing date plates from 1970s motorbike frames before sandblasting or powdercoating, (although I am not a fan of powdercoating myself) without damaging the underlying plate. Some of the other cunning ploys with wood chisels and protective washers sound pretty useful too.

Thinks

a suitably rough-textured ‘dimple’ in the end of a bit would allow the use of an Impact Driver in undo mode.

… I wonder if there is a die-grinder burr that might be adapted ?

MichaelG.

.

Edit: __ see here for inspiration

https://www.eternaltools.com/cup-burrs

Edited By Michael Gilligan on 07/01/2023 09:35:51

The problem is that in many examples, the “thread” helix angle is too steep to allow unscrewing by a pure rotary torque. It jams instead because the component of force generated along the helix direction is less than the friction caused by the torque. Thus some added axial extraction force is needed. If the head is domed without a parallel diameter, this is difficult to apply.

Place a piece of thin wood against the plate and then lever the pin out with a tack lifter. That’s what I did and after painting the machine the plate was put back with the original pins. Easy.

I have 'done' quite a number of these drive-pins during my grinder refurbishment. Mine were dome-headed, very hard and had a very coarse helix. I did the sums and fully agree with Malcolm, attempting to unscrew them with friction produced by axial force in the 'wrong' direction is a lost cause. Pliers etc were tried but they wouldn't bite in to the dome, they just ended up scratching the plate.

I had to use a die grinder and carbide burr to carefully remove the heads so that I could lift off the plate. This leaves the problem of the remaining shank in the hole. Rather than try to remove this when the time comes to refit the plate, I will just make good the surface and reposition the plate a few mm away from its original position.

Gerry

It's getting the tack lifter into the zero gap between the head of the drive screw and the soft aluminium data plate without scarring it that defeats me.

Hi. My original question was due to me taking the data plate off the headstock of my CZ motocross machine prior to having it powder coated. I was able to get behind the fixings and lever them part way out with a bar. Then an old wood chisel under the head.

I will NOT now attempt the data plate on my Colchester lathe when I refurbish it, after reading the comments above, it's too risky.

Well, it certainly provoked some comments and thanks to everyone who joined in.

Regards.

Know thine enemy …

Type U is illustrated here: **LINK**

https://www.gracesguide.co.uk/File:Im1943MWYB-Nettle.jpg

MichaelG.

Stephen.

I have a selection of these Drive Screws. If you can let me know the size you require I may be able to supply what you need.

Keith.

Edited By Keith Rogers 2 on 08/01/2023 17:51:11