On 10/02/2020 14:33, Bert Coules wrote:
"charles" wrote:

Screwfix have Rawlbolts with a fixture size of 75mm in M10. they also do
M12 with a 60mm fixture size.

Thanks, but the baseplate holes are drilled for M6; I'd rather not open
them up as far as M10 or 12.

You should consider doing so. Use a step drill. When I was employed
fixing TV wall brackets in hospitals it was normal to drill out the
little holes in the backplate. I don't know why the put some small holes in.

Bill