nuts and screws

[lionelmcc]

OK can some of you experienced guys do some jargon busting for me regarding screw sizes?

The ones we affix sockets to boxes for instance M ,,,,, what?
The little ones that fix the covers onto central heating controllers ( can the nuts be obtained for these?).
the brass ones pan heads for conduit boxes?

any others I haven' thought of?

L

 

[Guest123]

Hey.

Faceplate screws are M3.5
Conduit box screws are M4

As for the heating ones, not really sure.

Another one is the gutter bolts we use sometimes for joining tray, earthing the banjo ring on a SWA they are M6.

Cheers

 

[Mr Mark Sparks]

m stands for machined thread 3.5/4/6 is mm if the central heating screws have a neat thread they are m something,
old m4s were 2ba there were 4ba also but im not quite that old

 

[lionelmcc]

thanks chaps

Can nuts be purchased for all these sizes?
Especially for the little ones that fix the covers on heating controllers. They are really hard to find if
one falls out.

 

[Mr Mark Sparks]

anything that has an m thread will have a nut available.

 

[Bernieg]

The subject of nuts and bolts is massive. Thank goodness we generally now only use Metric

The M stands for British Standrd ISO Metric. so a M6 screw is a metric screw of 6mm dia and threaded all the way up the shank..

The following may be helpful in identifiying some metric thread sizes by the width of the screw head across the flats.

M1.6 screw is 3.2mm across the flats
M2 screw is 4.0mm across the flats
M2.5 screw is 5.0mm across the flats
M3 screw is 5.5mm across the flats
M4 screw is 7.0mm across the flats
M5 screw is 8.0mm across the flats
M6 screw is 10.0mm across the flats
M8 screw is 13.0mm across the flats
M10 screw is 17.0mm across the flats
M12 screw is 19.0mm across the flats

A screw has a thread all the way up the shank but a bolt has a thread only for part of the shank.

BA screws (British Standard Association Thread)

2BA were used on old conduit boxes (circular)
4BA were used on old switch and socket boxes

I would guess that the screw size on the central heating control unit would be 2mm.

Just a point on wood screws, a number 8 size wood screw would be 8mm across the width of the head, and a number 10 wood screw would be 10mm across the width of the head, etc etc

And yes, as Markspark666 says all metric screws and bolts will have nuts available.

I hope this helps

 

[lionelmcc]

thanks guys

I know there must be nut available,,,,,,,,,, BUT WHERE????????

what about A2 etc