Problem replacing old style cooker socket

[Jackal6]

Hello,

I have been trying to replace an old style cooker socket with a new one (still the old style but a new one).

I have wired it all up but when i tried to screw the socket onto the back plate the screws won't fit into the lugs on the back plate. They start to go in but become too tight.

They look the same size as the screws from the old cooker socket but they must be slightly bigger. I found a nut that fits onto the new screws and it also fits onto the old screws so there must only be a small difference in the sizes.

I can't take the new screws off the socket and use the old screws because they have a washer attached near the head of the screw to keep them in place.

I'm thinking about cutting the screws off, drilling the lug holes out slightly and using machine screws and 2 nuts on each.

Here are some pictures of the screw and lug (the bottom picture is the screw on the old socket):

Untitled

• Jackal6
• 14 Jan 2011
• 1

Untitled

• Jackal6
• 14 Jan 2011
• 1

Is there anything else i can try to get around this problem?

Thanks for any help.

 

[RF Lighting]

It's more than likely that as you have an old back box it will have imperial threads on the lugs you're trying to screw into, and your new switch will have been supplied with metric screws.

If you can find out what thread the new screws are by screwing a nut onto them, then you could rethread the backbox with a metric tap.

If you don't have any taps, you can cut the washers off the new and old screws, and use the old screws to screw your new switch back.

 

[Jackal6]

It's more than likely that as you have an old back box it will have imperial threads on the lugs you're trying to screw into, and your new switch will have been supplied with metric screws.

If you can find out what thread the new screws are by screwing a nut onto them, then you could rethread the backbox with a metric tap.

If you don't have any taps, you can cut the washers off the new and old screws, and use the old screws to screw your new switch back.

Thanks for the help, i haven't got any taps but i've just snapped the washers off the screws and used the old screws and some new washers and the switch went back in fine.

Thanks again.

 

[ban-all-sheds]

If you can find out what thread the new screws are by screwing a nut onto them, then you could rethread the backbox with a metric tap.

Would they not be M3.5?

 

[MrTinker]

Well re-threading would be best, but a M3.5 m/c screw into a 4BA threaded fitting will go, with a little bit of brute force and ignorance, considering 4BA has a major diameter of 3.5992 mm but has a slightly different pitch(0.0604mm differance to be precise)

 

[sparkwright]

They will be larger than 3.5 mm.

 

[sparkydude]

Old MK cooker switches have 2BA threads and so the nearest metric equivalent is an M5, but yu need to tap the hole sout first .

They are definitely not M3.5


Nick