Glossary

A Grade 2 fastener is a low-carbon steel bolt or screw that represents the basic, entry-level strength grade in the SAE (Society of Automotive Engineers) grading system used primarily in the United States. These fasteners are typically made from low-carbon steels such as 1006, 1008, or 1010 and are not heat-treated, which keeps their strength lower but makes them inexpensive, ductile, and suitable for general-purpose applications.

In industrial and fastener-distribution environments, Grade 2 fasteners are considered non-critical, light-duty hardware. They are commonly used in non-structural, non-load-bearing assemblies, household applications, light machinery, basic construction, appliance manufacturing, and farm equipment where high tensile or shear strength is not required. Their typical mechanical properties include a minimum tensile strength around 60,000 psi for bolts under 1" diameter and roughly 55,000 psi for bolts 1" and above—significantly lower than Grade 5 or Grade 8.

Grade 2 bolts are usually identified by a plain head with no markings (hex bolts without radial lines). In distribution, they are often supplied zinc-plated, hot-dip galvanized, or plain and are widely stocked due to their versatility and low cost. For situations requiring structural integrity, vibration resistance, high torque, or elevated temperature performance, Grade 2 fasteners are not appropriate and are replaced by higher-grade fasteners like Grade 5, Grade 8, or alloy/metric equivalents (Class 8.8, 10.9, etc.).