The A2-19-14-A1 is a part of the Society of Automotive Engineers (SAE) Standard Code of Information (SCI). This standard is used to define and assign a numerical code to describe the strength, size, temperature, and pressure ratings of metallic and nonmetallic mechanical fasteners and related products. A2-19-14-A1 specifies the minimum values for hardness and tensile strength for a carbon steel fastener with a hex or socket head. The numerical code values are based on the grade designations of a given type of fastener material or product.