measuring and cutting screws shorter

[James Hanley]

Where in the uk can I order a steel scale to measure my screws accurately from below the head? like this one

would I go about cutting screws to make them shorter, would a saw ruin the screw?

what screw is best for screwing into steel? alu, brass, steel? It'd be good if the screw didn't conduct electricity.

thanks

[mike ring]

[e-mail] (James Hanley) wrote in news: [e-mail]:

Put a nut on the screw (I presume a better word is "bolt"}

Saw it; tidy it up with a file, screw the nut off to reform the thread.

Any insulating bolt is so much weaker than steel it doesn't matter, otherwise, surely steel?

mike

[Set Square]

devices which will do what you want.

Are you talking about woodscrews, or parallel-sided machine screws? If the latter, the trick is to screw a nut onto the screw *before* shortening it. Then cut it to length with a hacksaw. Then file the end as flat as you can. Finally unscrew and remove the nut. As it passes the cut end, it will clean up the threads.

Woodscrews need a point on the end - and are never the same again once you start chopping them.

Are you talking about screwing into solid blocks of material, or thin sheets?

If thin sheets, use self-tapping screws. You need to drill a pilot hole which is just a bit smaller than the screw. These screws are made of steel and *will* conduct electricity.

For solid material, you will need to drill a pilot hole and use a tap to cut a thread in the material, in order to use machine screws. You can get machine screws in various materials - steel, brass, etc. - or even plastic if you want it to be non-conducting. A lot depends on what it has to hold - plastic screws are not as strong as steel ones.

[Bob H]

Do you want a steel tape measure? Is that what you mean? Steel scale? Tape measure?

You can use a hacksaw if they are metal. Whatever sze the screw is, thread a nut of same size onto it first before you cut the screw, then you can un tread the nut off the screw which should keep the treads ok.

All metal screws, brass, copper, steel, iron will conduct electricity. You need a nylon screw from an electrical outlet.

Hope that helps

[Tom]

Run a nut on to it, apply a fine hacksaw, unscrew the nut, file the end into a dome shape.

Use Nylon screws.

[James Hanley]

machine screws. dunno if they're parallel sided. I'll be screwing them into HDDs and Cases and cd drives. That's why I want non-conducting, in case they're long and hit a PCB, and that's also why I want to shorten them. I'm gonna get/make thumbscrews.

would a plastic nylon screw hold a HDD and CD drive securely without vibrations(seems like it should), dunno why they aren't standard - since metal ones can be too long, hit the PCB and short the device.

[James Hanley]

can I hacksaw and file a nylon screw? if not, then how would I shorten it?

thanks

[Set Square]

Yes.

[Set Square]

I don't see why you shouldn't be able to use nylon screws for this purpose.

I always thought that the screw holes in HDDs and CD drives were blind - rather than going right through to the internals. Are you *sure* this is real problem?

[Tony Williams]

Scalpel.

Assuming you can easily get nylon screws in American threads.......

[Anon]

definitely. I've often tried screws from 1 cd drive in another drive and the other one has shorted. Same with floppy drives. The hard drive specs on the seagate website for example (for at least one of their models and perhaps all of them), specify that screws be no longer than around 4mm long (well, the ones on the bottom - should one choose to screw the drive in from the bottom - can be about 5mm).

Also, HDDs take #6 screws and CD drives #4 (in all the cases i've seen).

So i'm going for an antec case with removable drive rails for the

5.25" bays and #4 nylon thumbscrews for the 3.5" bays. I'm going to avoid cases with 'screwless' designs. I'd like to use thumbscrews on removable drive rails in my 5.25" bays too but i'm sure the drive won't be able to slide out with those knobs in the way - since the drive(with rails screwed on) fits snugly and slides out snugly!

[N. Thornton]

a fine example of wasting everyones time by not giving the relevant info. for HDDs all you need do is buy a pack of the proper screws. Cutting down longer metal ones is a complete waste of time. Nylon ones will not be strong enough because the amount of metal gripped is so small.

The only thing that stops mounting screws hitting electrical internals is length of screw. You typically get perhaps 5 or 6mm to play with.

NT

[Mike Harrison]

Put a nut on before sawing - when sawn, take the nut off and this will cut off/straighten out swarf from the sawn edge

For nonconductive, nylon is about the only option - you can get ceramic screws but they cost many pounds each (RS do them if anyone's interested..)