James B | 09/01/2011 20:22:37 |
![]() 101 forum posts 14 photos | Hi All,
Hopefully a quick answer for someone...
I am currently trying to drill out a blind rivet on a machine casting that is holding the belt speeds plate on - but they are either hard or work hardened - either way a HSS drill wont touch it.
I have looked at Carbide drills, but only ones of the right size (1.6mm) I can see are listed as PCB drills - are these up to the job?
Any advice gratefully received!
James |
Dusty | 09/01/2011 20:50:26 |
498 forum posts 9 photos | James
These are something called a drive pin. They are a blind rivet as you say but they have helical serations on them (rather like a very coarse thread). They could be described as metal nails as they are driven in with a hammer. They are almost impossible to remove. The only way that I know of to remove them is to try and remove the belt speed plate without damaging it too much. Then make up a tapered wedge to go under the head. Then gently tap the head of the drive pin while taping the wedge in. There is the danger of bursting the casting and you end up with a crater. For your information the hardness is like a masonry nail. I would have thought drilling was a non starter. I would be tempted to grind the head off, remove the plate and when replacing it move it up or down 5/6mm and re-drill. |
Alan Worland | 09/01/2011 20:58:00 |
247 forum posts 21 photos | I have managed to remove a couple of these. Try and get a punch on the side of the head and tap 'around' the rivet which will have the effect of enlarging the hole - you may then be able to get it out.
If not, the above sounds a good alternative! |
Billy Mills | 09/01/2011 21:04:31 |
377 forum posts | James, You might be able to grind most of the head off with a cutting disk then drill out the centre with a soild carbide drill but carbide drills at this size don't like any sideways force at all - non starter for a handheld drill. A cheap diamond disc in a Dremmel might be worth a try. Regards, Alan. |
Dennis R | 09/01/2011 21:08:19 |
76 forum posts 16 photos | Have managed to lever several of these out with a Stanley knife, just gently slide or tap the sharp edge under the edge of the plate, lever slowly and the rivet twists out - with luck.
Hope you manage.
Dennis |
Nicholas Farr | 09/01/2011 21:29:52 |
![]() 3988 forum posts 1799 photos |
Yes they can be removed by a bit of tinkering, I've managed to get a good grip on the sides with a decent pair of pliers and twisting, but it doesn't always work. A little leverage under the plate can help if you can get something thin enough to start. If you've got a Dremel type tool, you might be able to cut a slot in the head and use a screwdriver to loosen it up a bit. But if all else fails, just grind it off, like what has been said.
Regards Nick. |
James B | 09/01/2011 21:50:43 |
![]() 101 forum posts 14 photos | Hi All,
Thanks for all the tips - to be honest, didn't think pulling them out was an option so hadn't tried.
I'll have a go tomorrow with some of your suggestions - one of the plates I need to remove is damaged and I have a replacement, so I can start with that one.
I'll let you know how I get on!
Thanks again,
James
|
peter walton | 09/01/2011 23:48:58 |
84 forum posts | Try a dremel with a sloting disk, cut a groove accross the head then use a straight blade screwdriver you only have to turn them a little then grip with Molegrips.
Peter |
Ian S C | 10/01/2011 11:44:00 |
![]() 7468 forum posts 230 photos | possibly better than a slot, a pair of flats on the side of the head to get a good grip with the vise grips, although you havn't got much metal to work with. Ian S C |
James B | 12/01/2011 12:53:55 |
![]() 101 forum posts 14 photos | Hi All,
Thanks for help on the above. Because one on the plates was in a recess, access was a bit limited for mole grips on some of the pins - so I went for the cut off wheel in the dremel to cut a small slot in the head.
Appropriate screwdriver and a good downward pressure and all drive pins are out, without damage to the plates!
Thanks again,
James
|
The Merry Miller | 12/01/2011 13:44:17 |
![]() 484 forum posts 97 photos | The correct term for the item is "Hammer Drive Rivet" I only used them in the past for securing ally labels or the suchlike into an ally base mainly on military equipment. As the preceding posts intimate, they are not meant to be removed. |
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