those little, plastic, drill bit 'centre finders'

[Keith (Dorset)]

Can someone please tell me absolutely exactly how to use those little, grey, plastic tube-type things with springs inside - which I believe are 'centre-finders' and come provided in drill sets.

I spent ages searching on the web last night and only found a vague reference and lots of info on drill centers for lathes and milling machines.

Thank in advance,

Keith

[Dave Jones]

Do you have a pic?

[Paul Andrews]

Are you referring to a plastic collar that you put onto a drill bit to mark the depth before you drill? If this is so, you slide the collar along the bit to the desired depth, then drill until the collar meets the surface.

Paul

[Mathew Newton]

I thought they were for holding the head of a screw on the bit prior to, and during, driving them in? Never actually used one though... (and have had the odd painful finger to prove it!)

Mathew

[mike ring]

"Mathew Newton" wrote in news: [e-mail]:

I don't think he means them, but if they get discovered from this thread I'll be well pleased; I used them yonks ago, they just sit on the stem of your tweaker out of the way, slide them down and they hold the head so you can start it.

Best little things ever.

Then they totally disappeared :-((

mike

[dave]

^^^^^^^ is this a technical term?

Perhaps they weren't described very well? :-)

[Rob Morley]

[mike ring]

Rob Morley wrote in news: [e-mail]:

Thanks for the try, Rob, but not them. Same sort of thing, but a fiver! and only for power drills.

They were little red plastic thingies, a cylinder to slide up the stem and

3 little flexible grippers extending towards the point. about a shilling (sic) each; I bought a few over the years, but they broke or got lost, I got them from my local electronics shop in East London mainly for my PO No.1, (you can tell I'm talking about the Golden Age); but they were so handy I thought they'd stay around.

I'ver been looking for twenty/thirty years, so I've no great hopes...

mike

[soup]

These things?

been meaning to ask what these were for, so shall follow this thread with interest.

[Rob Morley]

I knew what you meant, the one I linked to is the evolved form :-) That price is steep - you can get them for half that, maybe cheaper. You can use it in something like a Stanley Multi-Bit instead of a power driver.

I think that the proliferation of magnetic bits and cross-head screws has rendered them mostly obsolete.

[Nigel Molesworth]

Absolutely! But generally reserved for a small screwdriver, used to "tweak" a potentiometer or ferrite core.

[Rob Morley]

They're for plasterboard screws.

[Keith (Dorset)]

Thanks 'soup' - this is exactly what I meant.

Having established they are meant for plasterboard screws... how exactly does one use them / it?

Many thanks to all.

Keith

[mike ring]

Rob Morley wrote in news: [e-mail]:

But they worked on nonmagnetic screws, including nylon, and all sorts of heads, even grubscrews!

I just think it's Murphy's law, anything *really* good, *they* abolish

mike

[david lang]

Me too! I've found them it sets of driver bits and never known what on earth they were for.

Dave

[Rob Morley]

Stick the plasticky thing over the screwdriver bit, drive screw into plasterboard - when the plasticky thing comes up against the plasterboard the bit will slip out of the screw head.

[Nigel Molesworth]

I've just bought a pretty naff "250 pcs Power Tool Set" from B&Q, made by Performance. It was only about £16 (reduced from £25) so I figured it's worth it for a few throwaway bits etc.

There are 5 of these widgets inside, labeled "Screw finders". I think one end may fit over the bit holder, the other end has a internal serrated washer, held in place by a spring.