Glossary

Earnest Machine Products line of B7 Heavy Hex Cap Screws are manufactured to the material and physical properties specified by the American Society for Testing and Materials standard ASTM A193 for Grade B7. The overall dimensions are made to the requirements of ASME B18.2.1 for heavy hex cap screws.

A hex head cap screw is a precision-threaded fastener with a six-sided (hexagonal) head designed to be tightened with a wrench or socket. It’s one of the most common and versatile fasteners used in machinery, construction, and equipment assembly, known for providing a strong, precise, and reliable clamping force.

Unlike ordinary hex bolts, hex head cap screws are manufactured to tighter tolerances and often feature a machined washer face under the head and chamfered threads at the tip. These design details allow for more accurate torque control and even load distribution when the screw is tightened, making them suitable for critical or precision applications.

Hex head cap screws can be either fully threaded (threads running the entire length of the shank) or partially threaded (with a smooth shoulder section under the head), depending on whether the joint requires shear strength or maximum thread engagement.

They are typically made from carbon steel, alloy steel, or stainless steel, and can be heat-treated for high strength. Common finishes include zinc plating, black oxide, or galvanization for corrosion protection. Standard specifications include ANSI B18.2.1, ISO 4014/4017, and DIN 933/931, depending on the regional manufacturing standard.

Earnest Machine stocks this style of fastener in diameters ranging from 1/4” to 3” with lengths ranging from 1/2” to 20” with a wide selection of grades and finishes to choose from.

A Hex Head Cap Screw DIN 931 is a type of fastener that is partially threaded, featuring a hexagonal (six-sided) head, and conforms to the DIN 931 standard, which specifies the dimensions and requirements for metric hex head cap screws. These screws are used to secure two or more components together in mechanical and structural applications.

A Hex Head Cap Screw DIN 933 is a type of fully threaded fastener with a hexagonal head, conforming to the DIN 933 standard. This standard specifies the dimensions and mechanical properties for these screws, ensuring consistency and reliability in various applications.

A metric hex head cap screw is a type of fastener that has a hexagonal (six-sided) head and a threaded shaft, designed to be used with metric-sized nuts or tapped (threaded) holes. The hex head allows for easy tightening and loosening using a wrench or socket. These screws are commonly used in machinery, automotive, construction, and structural applications, where precise, strong, and reliable fastening is required.

A Metric Hex Head Cap Screw (ANSI) is a type of threaded fastener with a hexagonal (six-sided) head, used for securing materials or components. It is manufactured to metric dimensions and follows specifications set by the American National Standards Institute (ANSI). These screws are widely used in machinery, construction, automotive, and many other applications.