Glossary

Machine bolts are used to fasten wood to wood, wood to metal, and metal to metal. They are typically installed into pre-drilled and tapped holes and utilized in heavy-duty applications. Earnest Machine stocks Machine Bolts in grades 2, 5, and grade 8, providing options for applications requiring increased strength and durability. Earnest also offers Machine Bolts in various diameters, lengths, and finishes, including RoHS-compliant Zinc Clear Trivalent and hexavalent-free Zinc Yellow Trivalent.

A machine screw anchor is a type of fastener used to secure machine screws into masonry or other solid materials like concrete, brick, or stone, where a regular screw wouldn’t hold. It’s essentially a sleeve or plug that gets inserted into a pre-drilled hole in the material. When a machine screw is threaded into the anchor, it expands or grips the surrounding material, creating a strong, reliable mounting point.

Industrial machine screws are specialized fasteners used to secure components in machinery and equipment. They are designed for precise applications where reliable fastening is required, often involving the assembly of metal parts or the attachment of machine components. These screws come in a variety of sizes, materials, and head styles, making them versatile for different industrial needs.

A manufacturing process that removes material from a part to shape it into a specific design. In fastener production, machining is used to form precise dimensions, threads, or other features by cutting, drilling, turning, or milling the material with specialized equipment.

The largest diameter of a screw thread. For an external thread (on a screw or bolt), this is the measurement across the very outermost points or peaks of the threads, from one side to the opposite. For an internal thread (like in a nut or tapped hole), it represents the widest diameter of the thread profile, found at the highest point of its internal ridges. This fundamental measurement defines the fastener's basic nominal size.

A system of measurement based on meters, centimeters, and grams, used internationally. In fasteners, “metric” refers to sizes and dimensions measured in millimeters.

A metric flat washer is a thin, round, flat piece of metal or plastic with a central hole that corresponds to a metric-sized fastener, such as a bolt or screw. It is used to distribute the load of the fastener more evenly across the surface of the material being fastened, preventing damage, reducing friction, and ensuring a more secure connection.

A metric hardened flat washer is a type of flat washer designed according to metric dimensions (millimeters) and made from hardened steel. The hardening process involves heat treatment to increase the washer's strength and durability, making it suitable for high-stress applications. These washers are used to distribute the load of a fastener, such as a bolt or screw, over a larger surface area, protect the material being fastened, and reduce wear.

A metric heavy hex nut is a type of fastener designed with a hexagonal (six-sided) shape, similar to standard hex nuts, but with a thicker and larger profile. These nuts are commonly used in applications where additional strength and durability are required, particularly in high-load or high-stress environments.

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.

Hex Jam Nuts are half the thickness of standard Hex Nuts and are commonly used in applications where a nut with a low-profile thickness is needed. This nut can also be used with a standard Hex Nut to create a locking action in your assembly. Earnest Machine stocks the largest selection of Hex Jam Nuts in industry, offering both inch and metric sizes with a variety of strength levels, thread directions, and finishes to choose from.

Otherwise known as Lug Nuts, Wheel Nuts are specifically designed to hold tire rims to an axle. These nuts are primarily used in automotive and construction equipment. In order to match the rim, the nuts are engineered to 60 degree, 90 degree, and radius faces.

A metric nylon insert hex flange lock nut is a specialized fastener that combines several important features: a hexagonal shape, a built-in flange, and a nylon insert to provide a secure, vibration-resistant fastening solution. This type of nut is commonly used in applications where both high torque and resistance to loosening are important.

A metric nylon insert hex flange lock nut is a specialized fastener that combines several important features: a hexagonal shape, a built-in flange, and a nylon insert to provide a secure, vibration-resistant fastening solution. This type of nut is commonly used in applications where both high torque and resistance to loosening are important.

A microscrew (miniature screw) is a very small machine screw used to fasten tiny components where space and weight are limited—think electronics, wearables, cameras, watches, and medical devices. In practice, people usually mean sizes ≤ M2 in metric (e.g., M1.6, M1.4, M1.2, M1.0, M0.8) or #0-80 and smaller in inch series (down to #0000-160). They’re made in common head styles (pan, flat, button, socket), drives (Phillips/JIS, Torx®, slotted), and materials like stainless steel, titanium, and brass, with finishes such as passivation or black oxide.

Because everything is tiny, installation uses low, precise torque (often measured in cN·m/N·cm), fine thread classes, and magnified/ESD-safe handling. Variants include thread-forming microscrews for plastics and micro set screws for collars/gears. The key idea: a standard screw in every way—just engineered for microscale assemblies with tight tolerances.

A standard or specification developed by the U.S. Department of Defense that defines the performance, quality, and testing requirements of a product. Fasteners labeled “Mil-Spec” must meet strict requirements for material, strength, corrosion resistance, and uniformity, ensuring reliability in defense and aerospace applications.

The smallest diameter of a screw thread. For an external thread (on a screw or bolt), this is measured across the deepest points or valleys (also called roots) between the threads. For an internal thread (like in a nut or tapped hole), it is the diameter measured across the innermost tips of its threads (which are the deepest points of the internal thread profile). This diameter is crucial as it determines the fastener's core strength and the minimum engagement required with a mating part.