Alloy Steel Fastener ASTM A193 Grade B7 Plain Finish Heavy Hex Bolt
ASTM A193 Grade B7 heavy hex head bolts are high strength fasteners manufactured from heat treated alloy steel AISI 4140/4142, quenched and tempered. Dimensional specifications are governed by ASME B18.2.1. Grade markings consists of both the grade symbol "B7" and the manufacturer's identification mark. Inch series fasteners meeting ASTM A193 Grade B7 specifications are typically used in flange bolting applications. ASTM A193 covers the requirements for high temperature and high pressure bolting. Heavy hex head bolts have a larger head to increase the bearing surface and distribute the clamping load over a larger area. Bolts listed that are smaller than 1/2" diameter may be finished pattern bolts. A193 B7 hex bolts, as well as all thread stud bolts having diameters above 1" are most common 8UN (8 threads per inch) and are also available UNC (coarse thread).
Heavy Hex Bolt Sizes & Thread Specifications
| Metric Sizes |
M12 to M152 |
| Inch Sizes |
1/2" to 8" |
| Metric Threads |
ISO, ASME |
| Imperial Threads |
ASME, BSW, BSF |
| Thread Standards |
ISO 68-1, ISO 268, ISO 724, ASME B1.1, ASME B1.13M, BS 84, BS 3643 |
Heavy Hex Bolt Standards
| DIN |
ISO |
ASME |
UNI |
| Imperial |
Metric |
| 6914 |
7411 |
B18.2.1 |
B18.2.3.7M |
5712 |
Company Profile
From 1989 to now, Kingmetal Steel focus on manufacturing and distributing pipeline products including piping, fitting, flange, valve and fastener in stainless, carbon, alloy and duplex steel.
Kingmetal has a factory to manufacture seamless stainless steel pipe from DN6 to DN600 and distribute seamless steel pipe and fitting from top brand manufacturers such as Baosteel, Hengsteel, Tiansteel and Pansteel etc.
All of products are strictly compliance with standard, 100% inspection passed including visual, dimension and PMI test before shipment.
Both our sales and logistic teams are over 10 years of experiences and training frequently.
After- sales service with high efficiency, if any products are short quantity/weight or damaged caused by manufacturing, design or transportation can be compensated
Audited Supplier 
Audited Supplier 
){kind=link}
){kind=link}