Pb fastener zinc plated steel mf spacers m3 packs of 10 pb fastener s45530x20 these zinc plated steel mf spacers m3 x 20mm from pb fastener amp components are 20mm long hexagonal m3 tapped spacers manufactured to a high standard using galvanised steel and designed with a 1x 6mm external male thread and 1x 7mm internal female thread at each end these quality spacers fit a 55mm spanner opening and come supplied in packs of 10 pb fastener s45530x20 zinc plated steel mf spacers m3 x