Glossary

A C-type washer (also called a C-washer or slotted washer) is a washer that has an open slot cut out of it, forming a “C” shape rather than a complete circle. This open design allows it to be installed or removed without completely removing the bolt, screw, or shaft.

Cadmium plating is a metallic finish applied to fasteners through electrodeposition (also known as electroplating). This finish offers excellent corrosion resistance, especially in marine and aerospace environments, and provides good lubricity for consistent torque-tension performance. However, cadmium is toxic and environmentally hazardous, leading to its highly restricted use and replacement by safer alternatives.

Appearance - Cadmium typically has a bright silver or dull gray appearance.

Carriage bolts, technically called Round Head Square Neck Bolts, are used in many industries in a multitude of applications, from high stress plow applications and in mining and rock quarry shaker screens to lower stress wood assemblies such as bolting together picnic tables. Carriage Bolts are perfect for assembling all types of material from wood, plastic, or hardened steel.

A Carriage Bolt DIN 603 is a metric standard fastener defined by the DIN 603 specification from the German Institute for Standardization (Deutsches Institut für Normung). It is commonly used in woodworking, construction, and metal-to-wood connections where a smooth, finished appearance on one side is desired.

A heat treatment process that hardens the outer surface of a fastener to resist wear and abrasion while keeping the core softer and more ductile (flexible). This combination provides a hardened, wear-resistant exterior and a flexible core that helps absorb impacts and resist cracking or breaking under stress. This balance improves overall durability by combining hardness with some internal flexibility.

A cement board screw is a specially designed corrosion-resistant screw used to fasten cement backer boards (like HardieBacker or Durock) to wood or metal framing. These boards are commonly used as underlayment for tile installations in areas prone to moisture, such as bathrooms, kitchens, and laundry rooms.

A chamfer is a transitional edge between two surfaces, typically created by cutting or grinding the corner at an angle, most commonly 45 degrees. Chamfers are used to remove sharp edges, improve aesthetics, facilitate assembly, and reduce stress concentrations. For fasteners, chamfers are often applied to the ends of bolts or screws to help guide the part into a hole or make it easier to start threading a nut onto the fastener.

The angle at which the edge or corner of a part is cut or ground to create a beveled surface, commonly set at 45 degrees but varying based on design needs. In fasteners, this angle helps facilitate easier installation by providing a smooth lead-in edge.

A chemical patch is an anaerobic adhesive applied to the threads of a fastener. Anaerobic adhesives cure (harden) when confined between metal surfaces and sealed from air. When the patched fastener is assembled with a mating part, the adhesive activates and locks the threads together, helping prevent loosening caused by vibration or movement. Chemical patches offer consistent thread locking, eliminating the need for additional liquid adhesives during assembly.

Markings or grooves that run around the outer edge or face of a nut, following its circumference. These lines often appear as curved or half-moon-shaped grade markings used to indicate the strength classification of nuts, such as those specified in the SAE J995 standard for inch-series hex nuts.

An industrial clamp is a mechanical device used to hold, secure, or position objects tightly together to prevent movement or separation. They are essential tools in manufacturing, construction, welding, woodworking, and many other industrial settings. Industrial clamps come in many types, each suited for specific applications, and they are often designed to withstand high pressure, vibration, or heat.

The amount of force a fastener applies to hold parts together when tightened. It’s the compressive load that keeps the joint secure and prevents the parts from separating under stress.

A clear O-ring is a type of sealing ring made from a transparent or translucent elastomer, typically used where chemical resistance, visibility, or non-contamination is important. Like all O-rings, it serves as a mechanical gasket that fits into a groove and compresses to seal against liquids or gases.

An industrial clip is a broad term referring to any clamping, securing, or fastening device used in industrial settings to hold or position components, cables, pipes, panels, or other materials. Unlike traditional fasteners (like bolts or screws), clips often allow for quick attachment or removal without tools.

Popular in the agriculture industry, Clipped Head Plow Bolts have helped transform the agriculture industry. In many cases, these bolts are used to attach plow shears to agricultural plows, allowing the tractor to churn up dirt and break up the soil — burying crop residues and controlling weeds. The bolts are treated to Grade 5 standards to provide additional strength to get the job done.

A computer-controlled machine that shapes and cuts materials, usually metal or plastic, by spinning the part while cutting tools stay in place. The word CNC is short for Computer Numerical Control, which means the machine follows programmed instructions to do the work automatically. These lathes are often used to make symmetrical parts like shafts, bushings, and fasteners, offering reliable precision and consistent quality.

A computer-controlled machine that's used to precisely cut and shape materials, typically metal, plastic, or wood, by moving a rotating cutting tool across a stationary workpiece. The word CNC is short for Computer Numerical Control, which means the machine follows programmed instructions to do the work automatically. CNC mills are commonly used to produce complex parts with flat surfaces, slots, holes, and contours with high accuracy and repeatability.

A coil threaded rod is a type of metal rod that is fully threaded along its length and designed specifically for use in concrete formwork and construction applications. Unlike standard threaded rods, a coil threaded rod uses a specialized thread profile (coil threads) that is heavier and more durable to withstand the stresses of repetitive use, particularly in environments where frequent assembly and disassembly are required.

A manufacturing process that shapes metal wire or rod into fasteners at or near room temperature, using high pressure and specialized dies. This method deforms the metal without heating it, resulting in increased strength, excellent surface finish, reduced material waste, and high production rates. It's a primary method for creating bolts, screws, nuts, and other common fasteners.

A specific type of cold-forming. This process is primarily used to create the head of a fastener, such as a bolt, screw, or rivet. The head is formed by rapidly striking or compressing a short piece of metal wire, known as a blank, at room temperature, forcing the material to flow into a desired shape within a die. Like all cold-forming processes, this method increases the fastener's strength and produces parts with minimal material waste.

Concrete nails are hardened steel nails specifically designed to penetrate and hold in concrete, masonry, or brick. They are much stronger and more brittle than ordinary nails, allowing them to drive into tough materials without bending.

Conical Keps Lock Nuts feature a free-spinning nut and an integrated conical spring lock washer designed to prevent loosening caused by vibration. When tightened onto a bolt, screw, or stud, the spring action of the conical washer creates resistance against rotation. The added spring tension helps maintain a secure assembly and is suitable for light-duty automotive and machinery assemblies where vibration is a concern. This fastener is similar to the External Tooth Keps Lock Nut with the added advantage that the spring lock washer will not scratch or damage its installation surface.

The gradual deterioration or breakdown of a material, usually metal, caused by a chemical or electrochemical reaction with its environment, such as exposure to moisture, oxygen, or chemicals.

Cotter Pins are commonly used to lock slotted nuts into place in high-vibration applications. The pin slides through the bolt’s tap hole and in between the slots on the nut, preventing the nut from backing out. Earnest’s Cotter Pins are designed with an extended prong style and chisel point for easy insertion.

A Crescent Spring Washer—also known as a C-washer or curved spring washer—is a type of washer shaped like a slightly curved disc (resembling a crescent or shallow arc). It is used to provide light, continuous spring pressure between fastened surfaces, helping to maintain tension and absorb vibration.

A machining process where a hole is drilled completely through a fastener, typically perpendicular to its axis. This hole can pass through the fastener's shank or head and is used to insert a locking device, such as a cotter pin or safety wire, to secure the fastener in place.

A chemical process in which individual polymer chains are bonded together to form a three-dimensional network. In the context of fastener coatings, such as epoxy or PTFE, cross-linking typically occurs during the curing stage when heat or another catalyst causes the coating molecules to react and form these strong, interconnected bonds. This network of bonds improves the coating’s durability, chemical resistance, and adhesion to the fastener’s surface, making it more resistant to wear, corrosion, and environmental damage.

Occurs when the threads of a fastener (like a screw or bolt) and a mating component (like a nut or a tapped hole) are misaligned and forced together, causing the threads to cut into or deform each other improperly. This results in a damaged, weak, and often non-functional connection that can strip easily or seize, preventing proper tightening or disassembly. It is typically identified by resistance, grinding, or binding when attempting to start a fastener.

A cut nail is a type of square or rectangular-shanked nail made by cutting it from a sheet of steel, rather than drawing it into a round wire like modern nails. Cut nails were commonly used before the 20th century and are still favored in restoration, flooring, and masonry projects for their strong holding power and authentic historical appearance.

Cut threads are created by removing material from the fastener’s surface using a cutting tool, typically performed on a lathe or CNC machine. This machining process physically cuts into the material to create the thread form, rather than deforming or compressing the material like in rolled threads.

A secondary machining service that modifies fasteners by cutting them to a specific length, forming threads by either cutting (removing material) or rolling (pressing threads into shape), and adding a chamfer, which is an angled edge at the start of the fastener’s threaded section. This service customizes fasteners to meet precise application requirements.