ASTM A193 B7 Studs Double Head

Double End Studs, also known as double head studs, are cylindrical fasteners with threads at both ends. They find wide application across various industries including power, chemical, oil refining, valves, railways, bridges, steel structures, automotive parts, machinery, boiler steel structures, suspension towers, large-span steel structures, and large buildings. The diameter, length, and quantity of double end studs should meet specific requirements, and the type and material of these studs are determined by their grade.

There are two commonly used types of double end studs, each with two types of threads: coarse and fine. Coarse regular threads are represented by M followed by the nominal diameter, while fine regular threads are represented by M followed by the nominal diameter multiplied by the pitch.

According to fastener standards, M36 bolts use coarse threads, while diameters M36 and above can use fine threads with a pitch of 3.

Here are some general guidelines for the usage of double end studs:

• Double end studs with bm=1d are generally used for connecting two steel parts.
• Double end studs with bm=1.25d and bm=1.5d are typically used for connecting cast iron and steel parts.
• Double end studs with bm=2d are usually used for connecting aluminum alloy parts to steel parts.

The former type of connector mentioned above typically features internal threaded holes, while the latter type of connector has through holes.

When using double end studs with equal length threads on both ends, nuts and washers are required for two connected parts with through holes. One end of the welding Stud is welded to the surface of the connected part, and the other end (threaded end) passes through the connected part with a through hole. Then, a washer is installed, and a nut is screwed on to connect the two parts as a whole.

Common types of double end studs include B7 Double End Studs, SA193-B7 Double End Studs, High Strength Double End Studs, and American SA193-B7 Double End Studs.