J-Bolts are primarily used on long over hooked screens where it is very difficult to get tension in the middle of the screen. J Bolts stop the mesh from bouncing on the stringer rubbers and causing the mesh to fracture and break.
Product Description
J Bolt 16mm x 200mm J Bolt
(H/T 8.8) (130mm thread)
Includes Washer & Nylock Nut