14 February 2008

A Pet Peeve -- Proprietary Fasteners

As if it wasn't hard enough to keep tools on hand for the following screws:

- Flat blade

- Hex (in metric and fractional inch sizes)

- Philips

- Torx

- Tamper-resistant Torx (with a post in the middle)

- Torx Plus (with wider holes)

- Tamper-resistant Torx Plus (hard to come by -- with wider holes, a post in the middle, and five points instead of six)

- TTAP (a six-point variation with a deep hole in the middle, also hard to come by)

- Tamper-resistant TTAP (which I've never seen)

- Several other unusual fastener heads, such as square, two-pin, etc.

I've found that certain hard drive screws use a five-pointed variant of the six-pointed Torx star shape, which corresponds to "none of the above" and which doesn't seem to be available, anywhere. I found this out the hard way after buying a very nice set of Torx bits. The screws in question are so small it is very hard for my 40-year-old eyes to distinguish the five-pointed star from the six. They are roughly the size of a Torx T3 or T4.

The only reason I can imagine that manufacturers would use a fastener like this is sheer perversity. It isn't to make the devices tamper-proof -- the screws can be turned with a flat-head screwdriver of just the right width, although this is not ideal for either fastener or tool. Or, I could always just drill them out, as I've done on more than one occasion with a very stripped or damaged screw.

To the best of my knowledge the correct tool is not available for purchase _anywhere_ for a nobody like me, although I think you can sometimes find tools for larger versions of the bits for sale on eBay.

Several of these fasteners are apparently actually patented, and several apparently can't be legally sold except to properly licensed OEMs or other authorized personnel. Wiha sells, but will not sell to me, tamper-resistant Torx Plus tools, for example. And even if they would, they don't seem to have any this small.

As far as I'm concerned, such restrictions should be illegal. I'm sure there is an analogy here to be made to software APIs. I'm reminded of a talk I saw by Stallman, in which he drew puzzle pieces representing APIs, and talked about the evils of proprietary APIs. I bought it, I ought to have the right to take it apart!

By the way, the device in question is an iPod hard drive, made for Apple by Toshiba. But I'm sure there are many other variants of the same thing going on.


Jon said...

Fortunately proprietary fasteners are fairly easy to bypass. Use a nice Bic ball point pen, remove its innards and use a light to soften the hard plastic end. While the plastic is soft push it into the head in question, and voila, one perfectly fitting tool.
They do have a fairly short life, not helped by using pliers to turn them. Fitting it to then of a screwdriver helps ( also done while soft ).

Paul R. Potts said...

Thanks for the suggestion! I will have to try the plastic pen suggestion next time.

rhandwor said...

use search type in 22-9795
Use yahoo search type in SK 84231
These should have what you want.

david said...

For some time I've wondered:
When I design "open hardware", tamper resistance is unnecessary, and I can focus entirely on the technical problem of fastening.
For such "open hardware", what would be the optimum threaded fastener head pattern?

The Allen wrench for hex sockets makes other drivers seem unnecessarily complicated.
But wouldn't a similar wrench for a square socket (Robertson) be even simpler?

One nice feature of Philips is that it is "scalable" -- a single Philips screwdriver can fit a wide range of head sizes, it drops deeper into the bigger heads.
Most other heads seem to require a huge set of drivers, each one almost imperceptibly larger than the next.

Or is there some other head pattern that people will be using in a hundred years?
People who will wonder why it took so long for us to convert from such a mishmash of incompatible fasteners to an obviously superior head pattern?
Much like we use HTML and UTF8 today and marvel at the wide variety of now-obsolete, inferior, and unnecessarily complicated text markup languages and character encodings.