Pb fastener zinc plated steel ff spacers m4 packs of 10 pb fastener s57040x50 these zinc plated steel ff spacers m4 x 50mm from pb fastener amp components are 50mm long hexagonal m4 tapped spacers manufactured to a high standard using galvanised steel and designed with 2x female threads these quality spacers fit a 7mm spanner opening and come supplied in packs of 10 pb fastener s57040x50 zinc plated steel ff spacers m4 x 50mm pack of 10