Astm A307m (2026)
The specification defines two main grades that denote the intended application and mechanical properties: 1. Grade A
It is important to understand the limitations of A307M fasteners:
Think of it as the "general purpose" bolt. It is not the strongest bolt on the market (that honor goes to Grade 8.8 or 10.9), but it offers a unique combination of ductility, toughness, and cost-effectiveness that high-strength bolts simply cannot match. astm a307m
Fastening guards, covers, and frames on industrial machinery. A307M vs. Other Specifications
ASTM A307M is the standard for non-critical, low-carbon, metric carbon steel fasteners. Whether it is Grade A for general assembly or Grade B for flange connections, these bolts offer a reliable and cost-effective fastening solution. When designing, ensuring the correct grade is chosen based on the load and application requirements is essential. To help you narrow down the right fastening solution, Also,g., Hot-Dip Galvanized) (e.g., M12, M20) ASTM A307 - Portland Bolt The specification defines two main grades that denote
ASTM A325 is a high-strength structural bolt (
For anchor bolts, F1554 is the preferred, modern standard, providing better assurance of weldability and strength for foundation anchoring. Fastening guards, covers, and frames on industrial machinery
Unlike high-strength bolts, A307M bolts generally do not carry a traceable heat code or specific yield point on the head. They are usually marked with the manufacturer’s ID only.
Joining structural steel elements where high-strength bolts (like A325) are not required.
: They are often manufactured from A36 steel , which is inherently weldable. However, for guaranteed weldability, supplemental requirement S1 must be specified.
It is a common misconception to view lower tensile strength as a deficiency. For ASTM A307M, the lower carbon content and lack of heat treatment result in a material that is significantly more ductile. This ductility allows the fastener to undergo substantial deformation before rupture. In applications involving anchor bolts (Grade C), this property is invaluable. During seismic events or high-wind loading, the ability of an anchor bolt to stretch and yield without snapping provides the structural system with the capacity to absorb energy. Therefore, an engineer specifying A307M is often prioritizing toughness and elongation over pure tensile capacity.
