There are various fixings used with tensionable screen media such as:
Screen bolts, M16 or M20 both 130 long made from an 8.8 grade steel (these are not to be confused with Coach bolts that are made from a 4.2 or 4.4 grade steel)
Heavy Duty Plate Washer, M16 and M20
Conical Washers, M20
