... washer ,flat rib washer , 3 type rib washer used with B-form tie,B-cone , D cone ,hex nut to fix ... formwork we manufacture flat washer ,three shape washer which can be used with B- ... form tie,B-nut to fix formwork ... bolt ,implosion nut,wing nut,U-clip,hook,washer and other non-standard fastener most of them are ...