What is Bolts and Nuts

Tristar Bolts and Nuts
Studbolts 2

Fundamentals of Bolts and Nuts 

A bolt, unlike a screw, is usually accompanied with a nut and a washer in order to function as a fastener. Tightening the nut pushes the things you’re joining together, pressing the washer against one and yanking the bolt head against the other. When matching a nut and washer to a bolt, material, finish, size, and thread type must all be taken into account. 

Materials and finishes for bolts, nuts, and washers 

Steel is a common material for nuts and bolts however, if they will be exposed to moisture or pressure-treated wood, both of which may corrode steel fasteners, conventional steel fasteners must be coated with a corrosion-resistant coating. There are several popular do-it-yourself finishes: 

  • Zinc-plated bolts are resistant to corrosion but should only be used indoors. The finish is often thin, will not endure outside weather, and is not suited for use with pressure-treated wood. Yellow zinc or yellow dichromate forms a coating that protects the zinc plating from corrosion, but it is not suitable for outdoor use or when used with pressure-treated wood. 
  • Hot-dipped galvanized nuts, bolts, and washers are less prone to corrosion. These fasteners are intended for outdoor use and are suitable for use with pressure-treated wood. 
  • Powder-coated paint finishes are meant to be used on the interior. 
  • Black phosphate is a coating that improves paint adhesion.  
  • Black phosphate is a coating that improves paint adhesion.  Product information should include specific uses. 
  • Stainless steel is very corrosion resistant.  
  • Stainless steel nuts, bolts, and washers are often used in exterior projects and when dealing with pressure-treated wood.  
  • Hardened steel bolts are frequently used in automotive assembly due to their increased strength. 

Sizes of Bolts, Nuts, and Washers 

Bolt, nut, and washer sizes will be provided in metric millimeters (mm) or standard (SAE) inches (in). The diameter of a bolt is normally the outside diameter of the threads. Contrast the exterior diameter of a bolt with the inside diameter of a nut and washer. In SAE nuts and bolts, diameters of 1/4 inch or less are represented by a # and a whole number (a bolt with a primary diameter of 3/16 inch is a #10 bolt). The fewer the number, the smaller the dimension. 

The length indicates the distance between the end of the bolt and the underside of the bolt head, commonly known as the bearing surface. 

Thread Types for Bolts, Nuts, and Washers 

Nuts and bolts are threaded either coarsely or finely.  

  • Coarse-threaded nuts and bolts have more space between the threads, so match the threading of a nut to the threading of a bolt. They will be distinguished by a higher thread pitch. Coarse-threaded bolts and nuts may be fastened faster because they are less likely to get stuck or cross-threaded.  
  • Fine-threaded nuts and bolts with smaller thread pitches have less thread gaps, resulting in a tight, strong grip. A fine-threaded bolt’s nut is less likely to be dislodged by vibrations but installing or removing the nut will take longer. 

Types of Bolts 

Different bolts have different functions. Here are some of the most popular kinds of bolts used in DIY projects. 

Bolts with Hex Heads 

A hex bolt’s hexagonal head serves as a surface for grasping or twisting the bolt with a wrench, socket and ratchet, or drill/driver. Some hex bolts have threads that extend the whole length of the shank and are often used in threaded holes. They provide high grip strength because they distribute tension over the whole bolt. The thicker, unthreaded segment of a partially threaded bolt provides strength to the fastening process. Partially threaded hex bolts are also beneficial for operations that need more force to hold the work pieces together. Hex-head bolts are commonly used in construction and automotive applications. 

Bolts for Carriage 

The domed head of a carriage bolt provides it a smooth, polished appearance. It also adds a layer of safety and security since it does not have a driving surface like a hex-head bolt. Carriage bolts are fastened with washers and hex nuts after being inserted into predrilled holes. The nut is secured to the work piece by a square area under the head, allowing you to attach it with a single wrench, socket, or driver bit. Carriage bolts are used in a wide range of applications, such as decks, furniture, and outdoor playsets. 

Bolts for anchoring 

Anchor bolts are classified as either those meant for use in concrete foundations or those intended for use in a wall. L-bolts are intended for usage in wet concrete. While the concrete cures, the bolt is kept in place. L-bolts may be used to secure a deck post to a concrete pad. To secure retrofit anchor bolts in existing concrete, an adhesive is employed. When drilling into a wall stud is not possible, toggle bolts provide support for hanging things. 


U-bolts have two threaded shanks with a rounded or flattened appearance. Rounded U-bolts are used to secure pipe or conduit to a surface, while squared U-bolts are used to fasten things to a surface, such as a square post. The U-bolt is held in position against the item being secured by two nuts and a metal plate. 

Bolts for the eyes 

Eye bolts have a loop or ring end and a threaded end for attaching a chain or rope to a wood, metal, or concrete surface. Eye bolts are designed to be used in pre-drilled holes and come with a matching nut. Screw eyes are similar in appearance but have coarser self-tapping threads and a pointed tip that enables them to be driven into a pilot hole in a woodwork item. 

Bolts for hanging 

A hanger bolt is a fastener that does not have a head. It has machined threads on one end that accept a nut. The bolt’s coarse, self-tapping threads and a point on the other end allow it to be driven into a predrilled hole in wood or comparable material. 

Bolts that split 

Split bolts are designed to provide secure electrical connections. They enable the splicing of two wires as well as the connection of cables to terminals. Split bolts made of diverse materials work with a variety of wire types. Make sure your bolt is rated for the kind of wire you’re using. 

Bolts for the body 

Body bolts are often used in the automotive industry. They are used to attach fenders and other components to a car’s body. They have a hex head, a threaded shank, and a washer. 

Bolts for Axles 

Axle bolts attach wheels to machines like lawnmowers and wagons. The shank’s threaded end receives a locking nut, while the smooth section near the head allows the wheels to rotate. 

Types of Nuts 

Nuts work with different types of bolts to secure the fasteners. Although some nuts may be tightened by hand, the majority are designed to be driven using a wrench or socket driver. Here are some of the most often used bolt hardware nuts. 

Hexagon Nuts 

Hex nuts have a six-sided driving surface. They’re a common sort of nut used to connect wood and metal components with bolts of the same size and thread type. 

Lock Nuts 

Nylon lock nuts have a hexagonal head with an integrated nylon ring. When you tighten a lock nut onto a bolt, the threading of the bolt displaces or deforms the ring, causing friction and preventing loosening from slippage or vibration. A castle nut is a kind of locking nut that works by putting a pin or clip into a hole in the bolt. Rotation is restricted when notches etched into the nut come to rest on the pin. 

Wing nuts 

Wing nuts are designed to be tightened and loosened without the need of tools; the wings allow you to tighten and loosen them with your thumb and finger. These nuts are used to make adjustments and removals quick and easy. They may be found on drum sets, light stands, and other items that need to be adjusted on a regular basis. 

Cap Nuts 

Cap nuts, sometimes known as acorn nuts, are domed and feature a hexagonal driving surface. They are often hand installable. They screw onto the exposed threads of a bolt or threaded rod to protect them and provide a decorative look. Cap nuts may be found in projects like outdoor playsets and fences. 

Nuts in squares 

Because they have four relatively large driving surfaces, square nuts are easy to grab and spin. The nut’s form allows for a larger surface area to contact the fastening piece, providing better resistance to loosening and tightening. Use flat washers with square nuts to prevent the edges of the nuts from scratching the work piece. 

Once you have constructed and successfully constructed you LNG process and system, another step is to put them into use. One of the most popular usage of LNG process and system is in the Cogeneration Power Plant.