How do I undo this screw?

The security ones are usually used to discourage unqualified people from dismantling, however, the bits are widely available from Machine Mart and the likes of. Sometimes just one strategic screw.

The real cunning stuff are things like Apple's 'pentalobe'.

Neil

Thankfully not yet encountered Apple “pentalobe” but probably will at some point.

Dave W

The Pentalobe looks like a Torx only with five points. The drivers are commonly available though.

Lidl and Aldi sell security driver bit sets from time to time. They are only about a fiver and have security Torx, Spanner, Clutch, Tri wing, Spline and Robertson etc in several sizes.

the Apple pentalobe bolts are also used on a lot of Chinese built scooter's and motorcycles.....

not been able to get the larger size drivers, up to now managed to get the blighters undone in various ways but replace with normal metric headed bolts......mind have come across some weird thread profiles, so make new bolts it takes while as the taps and dies have come from all over......not nec. the best quality but when needs must...

A response on another forum suggested that Forward Industrial Products in Birmingham ***LINK*** might be able to help, so I phoned them. A very nice lady called Kelly said she would investigate and subsequently emailed to say they had 3 Uni-Screw bits and she would send me one free of charge even though they were as rare as Rocking Horse poo! She was as good as her word; the bit arrived by 1st class post and I've removed the screws.

That's what I call service.

Best possible result, Gary

MichaelG.

I had some equipment to repair, at first glance it was held together with Philips head screws, but when I looked closer they had only three lobes, I modified an old worn Philips screw driver with the Dremmel, and that work well, then today(a good few years on)I went to get a Philips driver, and when I got to today's job found I had the three lobe one.

Ian S C

I know it would not in your situation but my first inclination would be to use the "hot wrench" aka "gas axe"

If you choose to use some form of allen key (or any toolbit really) try a drop of a product called 'Screw Grab' which I have found to be a form of industrial magic. I am not 100% sure what it is exactly but I suspect microscopic chips of tungsten carbide in oil or colloidal suspension that bites into the toolbit and the job.. A tiny drop of the stuff on a toolbit has saved me many times. I've no association to the product, just a satisfied user. I've had a tube of the stuff for 20 years and still haven't used it up. I just googled and it comes in a bottle nowadays.

A mention was made of valve grinding paste, a similar idea but not sure if the carborundum is as "bitey" as this stuff is.

Thanks for the tip Steve. I have not heard about it before. Available on Ebay for $32 a bottle and says that it increases your grip by up to 800%.

Paul.

£6.49 on Ama***.co.uk

The torx security screws are easy to overcome, using a suitable pin punch the centre pin will snap at its base with a short tap allowing you to use a normal torx bit.

Martin P

Security screws must be a near pointless exercise as security bit sets are so widely available that every tinkerer must have a set.

Mike

"Security screws must be a near pointless exercise as security bit sets are so widely available that every tinkerer must have a set."

So true ! I think I paid about GBP10 in Aldi a few years back for a boxed set of bits. Must be over 50 in there including some weird & wonderful ones for fasteners I've never seen.
One annoyance though is when the designers place the "tamper-proof" fastener deep down inside a narrow hole as on most of my 2 stroke garden machines. The extension pieces for the bits/sockets are always just wider than the deep hole : - (