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How do I undo this screw?

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Neil Wyatt23/06/2018 12:41:24
15454 forum posts
651 photos
72 articles
Posted by Samsaranda on 22/06/2018 19:58:24:

Went to repair a UV unit that I use on my Koi pond with a new ballast unit and found that the screws holding the compartment panel for the electrics, had been changed on the later model from what was used before. Previous unit had just ordinary torx screws, later version had Secure Torx screws, which for the uninitiated are the same but have a pin located in the centre of the opening which takes the torx bit to unscrew it. The tool to remove them has a corresponding hollow to accommodate the pin in the driving bit, went on eBay and obtained the necessary driver bits but certainly frustrating, I know why they are used, it is so that manufacturers can frustrate anyone from tampering with or even repairing their units meaning that you buy another new one. Who keeps dreaming up all these oddball fasteners?

Dave W

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'.


Samsaranda23/06/2018 13:00:28
585 forum posts
4 photos

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

Dave W

Vic23/06/2018 15:07:19
1930 forum posts
10 photos

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.

clogs23/06/2018 15:50:39
434 forum posts
12 photos

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...

Gary Wooding12/07/2018 20:40:58
503 forum posts
105 photos

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.

Michael Gilligan12/07/2018 21:23:35
12524 forum posts
544 photos

Best possible result, Gary


Ian S C13/07/2018 12:25:25
7190 forum posts
227 photos

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

John Reese18/07/2018 00:42:30
629 forum posts

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

Steve Malikoff18/07/2018 05:53:30
1 forum posts

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.

Paul Lousick18/07/2018 08:55:13
955 forum posts
432 photos

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%.


KWIL18/07/2018 10:13:49
3048 forum posts
56 photos

£6.49 on Ama***

martin perman18/07/2018 10:39:30
1435 forum posts
60 photos

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

Mike Poole18/07/2018 10:47:34
1680 forum posts
43 photos

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


Fowlers Fury18/07/2018 16:04:34
293 forum posts
66 photos

"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 : - (

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