https://www.fastenerdata.co.uk/fasteners/bolts/more/bolts-g-to-r/roofing/metric.html
Fastenerdata - Metric - Roofing Bolt - BOLTS G to R - MORE BOLTS - BOLTS - DIMENSIONS - Fastener...
Fastener Technical Specifications, fastener source of supply, Comprehensive Fastener data, fastener knowledge, fastener history, fastener products and fastener...
bolts g to rfastenerdatametricroofing
https://www.toolstation.com/roofing-bolt/p43588
Roofing Bolt M8 x 30 | Toolstation
Zinc plated steel bolts with a cross pan head.
roofing boltxtoolstation