Hello again,
Sorry, I should have appended this to my other post about back boxes. In addition to the 35mm boxes I was asking about, I have also bought some of the ultra slim 13mm boxes. What size grommet fits the cable entry on these? I have tried squashing a 20mm grommet but it seems to be too big. I've had a search on line but the smallest I can find is
Thanks.
They usually come with 'oval' grommets. If you need the odd extra one cut down a 20mm open one.
Consider 25mm backboxes for light switches. Makes wiring simpler, yes it means a bit of chiselling but worth it.
I always use 25mm for switch, 35mm if any chance of a dimmer.
Squashing or searching?
Both ;)
To answer the other reply, I do try to use 35mm for everything where possible, following the advice on this group.
Thanks again for your replies.
or they come with the hole edge rounded into a lip, so gromet not required (and can't be fitted).
I think this is what I have here: one hole is already punched out and it does have a slight lip. On some boxes the lip is more obvious than on others.
Thanks.
On a different topic, I notice some of the 35mm boxes have both 20 and
25mm knock outs. It's a bit of a pain if the 25mm one is where you want to run a 20mm!Have something to add? Share your thoughts — no account required.
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