> -----Original Message----- > From: beowulf-boun...@beowulf.org [mailto:beowulf-boun...@beowulf.org] On > Behalf Of David Mathog > Sent: Friday, February 19, 2010 3:44 PM > To: beowulf@beowulf.org > Subject: [Beowulf] case (de)construction question > > Many rack cases have threaded standoff's directly attached to the case > metal. On the outside of the case one sees a hexagonal nut, and on the > inside the cylindrical standoff - with no sign of the hexagonal nut. We > even have one type of case with a removable motherboard tray, which is > quite thin, and even here this type of standoff is employed. > > The question is, how are these things put together,
Those are "self clinching fasteners" of one sort or another. PEMs from Penn Engineering (http://www.pemnet.com/) are the ones I've used " PEM(r) self-clinching concealed-head studs and standoffs install permanently in steel or aluminum sheets as thin as .062" / 1.6mm to provide strong and reusable threads for mating hardware in a wide range of thin-metal assembly applications. Their concealed-head feature contributes particular design benefits by allowing the side of the sheet opposite installation to remain smooth and untouched." http://www.pemnet.com/fastening_products/pdf/chdata.pdf reveals all. Those ones actually install in a blind hole, but there are other ones that insert in a through hole. http://www.pemnet.com/fastening_products/pdf/fhdata.pdf and more > specifically, how are they to be taken apart? They aren't designed to be dismantled. You can sometimes use a suitable press with appropriate dies to press the nut out, but the whole pressing the stud in process deforms the metal. Some of the standoffs are > in the way of a larger power supply that needs to go into one of these > cases. Is there a more elegant way of removing these than by grinding > them off or drilling them out? Saw and grind. Dremel tools are your friend. I have already tried unscrewing one, on > the theory the standoff might be threaded into the hex nut, but it > wouldn't budge. No, it's actually one continuous piece of metal. The hexagonal form factor is to allow the part to be clamped in the pressing process without spinning. > > Thanks, > > David Mathog > mat...@caltech.edu > Manager, Sequence Analysis Facility, Biology Division, Caltech > _______________________________________________ > Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
