I need to cut a 7mm solid Aluminium plug (Non-hollow and non-threaded) to replace a part in my car.

Is there a simple drill adapter tool to cut a solid metal cylinder (Plug) from an Aluminium mass ?

(Hole saw cutters are not in small sizes like 7mm)


Commercially these plugs are called "Solid Aluminium Rivets". But 7mm size is not available commercially (Available maximum size is 1/4" or 6.4mm). Actually head part of the rivet is not necessary for the function. It is needed for remove the plug for rebuild. But practically, that head got damaged when I try to remove it by a plug remover. So I had to drill-out the plug. So there is no photo to show. So, since the head is useless, I just need to make a plug to close the Idle port of my old carburetor.

  • $\begingroup$ I honestly don't really get what a cylinder cube is. A cylinder is a cylinder and a cube is a cube, but how do you want to merge that? A drawing could help alot. And why do you want a hole saw cutter for 7mm? 7mm drills are available everywhere. Taps and dies are also widely spread in M7. $\endgroup$
    – JE_Muc
    Oct 5 '17 at 16:44
  • 2
    $\begingroup$ Take some 8mm bar stock and turn it down to 7mm.. $\endgroup$
    – Solar Mike
    Oct 5 '17 at 16:52
  • $\begingroup$ Misspelling of "tube" maybe? But I think Dumindu is after a solid rod, not a tube (though it makes a lot more sense than "cube"). I'm not sure a drill, tap or die would help as it sounds like he's after the bit you'd remove with a drill. I think the hope is the hole cutter will produce a nice plug left in the middle of the cutter - though with those the "7mm" is likely to be the outer diameter, not the inner. And it'll be messy. I like Mike's idea above. $\endgroup$ Oct 5 '17 at 20:24
  • $\begingroup$ also consider a larger (common size) rod (eg 5/16 inch) and drill out the hole you need to fill $\endgroup$
    – agentp
    Oct 6 '17 at 4:52
  • $\begingroup$ Since this is really an automotive question rather than engineering, I suggest asking automotive groups. It may well be that there's not much internal pressure involved, so filling the hole with metal-epoxy might suffice $\endgroup$ Oct 6 '17 at 15:58

There are cutters that produce circular, slightly tapered plugs, typically 4-12mm diameter. Tapered plug cutter

Tapered plug cutter diagram

Used in a rigid drill press or milling machine with slow feeds and plenty of lubricant these can cut plugs from soft metals as well as wood and plastic.

  • $\begingroup$ Sorry.. I could' find such pug cutter for metals. Commercially there are ones for wood and tile. Can the one for wood be used for aluminium? $\endgroup$ Oct 17 '17 at 15:01
  • 1
    $\begingroup$ "Used in a rigid drill press or milling machine with slow feeds and plenty of lubricant these can cut plugs from soft metals as well as wood and plastic." $\endgroup$ Oct 17 '17 at 16:42

It depends a but what you mean by M7 size. Specifying M7 rather than 7 mm diameter implies that the hole is threaded. If this is the case you are better off with a bit of M7 threaded rod cut to length. The best material will depend on the application aluminium male threads are rare but do exist. In most cases stainless should be ok. If you do use a metal other than aluminium galavnic corrosion may be an issue but using thread locking or anti-seize compound should mitigate that pretty well unless it is constantly exposed to water or coolant (in which case a standard thread may not provide adequate sealing anyway).

If you do mean a plain 7mm diameter hole then you can just buy 7mm diameter rod and cut it to length, although getting it to stay in the hole may not be trivial and you might be better off tapping the hole anyway.

Edit : based on the additional information in the question I would be tempted to tap the hole with an M8 thread and use a grub screw with some thread locking compound as the plug. If sealing is an issue you could also use a button head set screw with a soft washer.

Actually if you set a 6.4 mm solid rivet properly it the shank should expand to fill a 7mm hole but it sounds like this will be difficult in this case as I assume you have limited access to the back side of the hole.

  • $\begingroup$ Sorry... I meant M7 as metric 7 size (7mm). There are no threads on it. $\endgroup$ Oct 6 '17 at 15:02

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