ASTM A325 structural bolts are commonly made in one of two ways, cold forged or hot forged. Both methods result in a product that is similar in appearance but is made using a completely different process. The more common size structural bolts, readily available on the market, are mass-produced in large quantities using a cold forging method.
Custom-size structural bolts in smaller batches are commonly made using a hot forging process. This is because the hot forging process is less automated and time-consuming. However, it is necessary if an A325 structural bolt is required that differs in size or configuration from what is available.
ASTM A193 B8M Bolts are defined as being manufactured to the American Society for Testing and Materials (ASTM) international standard A193. These bolts have the advantage of being rated for high-temperature and high-pressure applications such as boilers, pressure vessels and gas pipelines. Grades and classes classify ASTM A193 B8 bolts.
ASTM A193 B8 Bolts provides standard specifications for alloy steel and stainless steel materials for high-temperature service. At room temperature, A193 steel has a margin stress of 23,000 pounds (10432 kg) per inch. A193 steel can include carbon, nickel and silicone in small percentages to make it stronger. A193 bolts can be made from type 304 or 316 steel.
Hundreds of millions of structural fastening mechanisms are produced annually to ASTM International standards. Depending on industry requirements, contractors, steel fabricators, and steel erectors install these important infrastructure and construction components.
Until recently, structural fastening mechanisms were covered by six different ASTM International standards: A325 and A325M, A490 and A490M, F1852, and F2280. These standards covered steel and alloy steel bolts, as well as different sizes of bolt/nut/washer and threaded structural assemblies for tension control.
The working group would take a top-down approach to consolidation and, through reform, create a single new standard from the previous six. The new standard should address the requirements in the six old specifications while adding new information.
After producing the preliminary version that combined the old with the new, a solution was proposed to the F16 Executive Committee, which provided significant support. The proposal was also discussed with Stainless Steel Sheet suppliers in India that was very helpful in defining industry needs and providing relevant feedback. There would need to be a commitment from Committee F16 to make a significant change. Still, it would also require a commitment within the standard itself to have the opportunity to be approved by a committee vote.
Stainless steel fasteners manufacturers in India made up of respected growers, the general public, and users was instrumental in building a better standard and one with enough committee support to pass.
The result of ASTM task force, committee, industry, and staff efforts was the approval of ASTM A193 B6 Bolts, Specification for High-Strength Structural Bolts, Steel and Steel Alloys, Heat-Treated, with Metric or Imperial Dimensions. A new standard for structural bolts will replace the current six standards for structural fastening mechanisms.
The resulting document is an example of what can happen when a new perspective, cooperation and effort are combined in agreeing on a standard. The ASTM A276 Bolts retains virtually all of the previous technical requirements while adding necessary changes and enhancements. All of this was accomplished very effectively.