Helmet ear screw size

[Mikeyg]

Hi guys.
I've searched through different threats and cannot find a definitive answer as to what size the screws and nuts should be for the ears.
6-32, M3, M4, M3.5 are all mentioned, the only thing conclusive in all i've read is that they are countersunk.

Can anyone point me in the right direction please?
 

[ukswrath[Staff]]

Hey Mike, 3.5M however, the key spec is a 6.5mm head. I have found 3.5m screws here in the US with different size heads. This has been debated on several occasions and one fact agreed upon among some of us is the head size, regardless of the shaft size.

 

EDIT: "V" screw, flat head, slotted

 

Hope this helps 

[themaninthesuitcase[Admin]]

Metric screws tend to be based on standards, at least here, so if you get an M3.5 slotted countersink with it will comply with DIN963 which sets the sizes for everything.

 

But as said the only real crucial dimension is that head diameter, if its in the 6-7mm range, flat and has a slot I'd say it would be good enough unless you're going for a replica.

 

As you're in the UK I used these: https://www.spaldingfasteners.co.uk/metric-brass-countersunk-slotted-head-machine-screws-m3-m4-m6/ They are a touch long so will need to be cut down.  You will also want some washers and metric course nuts for them.