Screw expert required !

[Harrison-91xcg]

Hi
Trying to find some replacement hex screws for my cg lock.

I tried M3 - too small
M4 - too big
M3.5 - too big

Guessing I've got something wrong here ?

[The Wookie]

Disappointing thread...

Try an imperial one instead, ETA could be 1/8"

Edited by The Wookie on Thursday 2nd March 21:07

[steveo3002]

take it into a good fastener shop they will be able to sort it out

[anonymous-user]

What's a 'cg lock'?

[stevensdrs]

You need american sized screws.

[Big Al.]

Could be a 4BA, Tapping size is 3.0mm, OD 0.142" or 3.6mm

Taken from here:-

http://www.britishfasteners.com/threads/

[littleredrooster]

1/8" UNF perhaps?

[lucido grigio]

For what Whitworth ,this thread is crossed...

[Easternlight]

280E said:

What's a 'cg lock'?

Yes what is it?

littleredrooster said:

1/8" UNF perhaps?

They don't do 1/8" UN, threads under a quarter inch are number sizes try 5-40 UNC nominal .124" dia.

Edited by Easternlight on Thursday 2nd March 21:50

[Big Al.]

littleredrooster said:

1/8" UNF perhaps?

If he's going for UNF or UNC it's going to be either the 6-32 UNC or 6-40 UNF

Size 6 (both threads) give an OD of 3.5mm, the 32 and 40 denote TPI (teeth per inch)

again take from here:-

https://mdmetric.com/tech/thddat9.htm

Hope that helps.

[gazza285]

280E said:

What's a 'cg lock'?

Bondage device.

[Harrison-91xcg]

It's a device you attach to your seatbelt in order to lock it in like a harness (not as effective but massive difference especially if you don't have supported seats)

Would somewhere like screwfix be able to determine exact size ? Issue is were talking microns so my tape measure is useless

[Harrison-91xcg]

All's I know is that it's between m3 and m3.5

The old screws do have 4 dots on the head ?

[Little Pete]

lucido grigio said:

For what Whitworth ,this thread is crossed...

Excellent

[Big Al.]

Harrison-91xcg said:

The old screws do have 4 dots on the head ?

Any of these?

https://www.google.co.uk/search?q=4+dots+on+the+he...

Second link down Fastener Identification guide.

[littleredrooster]

Drill & tap it to M4 or M5?
ETA: What area are you? I've got a garage full of odd-sized screws/bolts/nuts/washers/taps
ETA2: ...and some digital calipers and thread gauges...

Edited by littleredrooster on Thursday 2nd March 22:10

[Oldandslow]

FWIW I'd suggest going the whole hog and drilling and retapping for a larger metric size. The original screws always seemed too small anyway and metric are so much easier to replace if you need different lengths or lose one.

[TooLateForAName]

Harrison-91xcg said:

It's a device you attach to your seatbelt in order to lock it in like a harness (not as effective but massive difference especially if you don't have supported seats)

Would somewhere like screwfix be able to determine exact size ? Issue is were talking microns so my tape measure is useless

Not screwfix (they dont do bolts that small) but an engineering supplier or model engineering supplies place. Take it in and you'll get sorted for under a £1.

[geeman237]

Try finding someone with some thread profile gauges like these.
A good machine shop should have them.
http://www.axminster.co.uk/metric-imperial-thread-...

[Harrison-91xcg]

Big Al. said:

Harrison-91xcg said:

The old screws do have 4 dots on the head ?

Any of these?

https://www.google.co.uk/search?q=4+dots+on+the+he...

Second link down Fastener Identification guide.

Thanks but that link doesn't appear to work ?