JBI is one of the leading professional screw manufacturers in Taiwan and specialized in manufacturing screws, bolts, nuts, washers, fittings, springs, and other hardware. All our products are produced according to the IFI, DIN, ISO International standard specification. Our fasteners are sold to the worldwide. We insist the high quality standard in order to maintain our products' reputation and safety request. We will offer the most reasonable prices to keep our customers in the most competitive situations. If you have interested in our square head bolt, please don't hesitate to contact us or browse our bolts category. Thank you.

Product Specification/Models
Size: 3/16"-3/4"& M4 to M30
Material: Carbon Steel, Alloy Steel, Stainless Steel, Brass
Grade: SAE J429 Gr.2, 5,8; ASTM A307Gr.A, CL4.8, 5.8, 6.8, 8.8, 10.9, 12.9
Thread: M, UNC, UNF
Finish: Plain, Zinc Plated(Clear/Blue/Yellow/Black), Black oxide, Nickel, Chrome, H.D.G
Packing: Bulk in cartons (25kg Max.) + wooden pallets or according to customer demand.

http://www.jbi.tw/category/bolts.htm