Bolts Manufacturer and Supplier

Reference our bolts size chart for detailed dimensional requirements.

Bolts are very strong fasteners that are normally employed together with washers and nuts. They have a head and a threaded shank and their size is determined by the diameter of the shank and the total length of the shank. Although there are many different types of them, the following are typical ones:

• Carriage Bolts: The Carriage Bolt is conical, with a shallow domed head, and a peculiar square shoulder below it, the bolts being arranged to ensure that the bolt does not rotate or pull through the metal on being installed, making it easy to tighten. It is used extensively in joining wood to wood or metal to wood, where its special locking system is used to provide assemblies that are clean and finished.
• U-Bolts: These are shaped like the letter U and have threads on both parallel ends which makes the U-Bolt essentially a specialized cradle or clamp. These threaded ends are not only covered with nuts to secure the bolts but also used widely to support and anchor cylindrical objects and are therefore important elements of securing the pipework, conduit, rope, chain, and auto parts such as vehicle leaf springs.
• Lag Bolts (Lag Screws): The Lag Bolt or Lag Screw is a heavy duty, self-tapping screw which has a sharp end and coarse threads and is not intended to be used with a matching nut. Very tough, it is meant to be driven directly as deeply as possible into wood, heavy composite material, and offers unparalleled shear strength to support heavy loads and is a very robust tool, e.g., decking, flooring, and holding heavy objects firmly to wood framing.
• Structural Fasteners: Structural Fasteners are a category of different high strength bolts carefully designed to function in vital, high stress structural assembly connections, and can often be better substitutes than conventional bolts. They come in a variety of sizes, and their purpose is to ensure safe connection between such materials as steel, wood, plastics, and composites, which present professionals with a safe and, in many cases, cost-effective choice in construction and large-scale infrastructure projects.
• Eye Bolts: Eye Bolts are nuts with a loop or eye in one end and threading on the other end, which are provided in both more durable forged and less sturdier bent types. They are fundamental elements in rigging, anchoring, pulling, pushing, and hoisting activities in both industrial and marine scenarios and are fundamental in that a rope, chain, or cable can be attached to a fixed anchor point.

To achieve different needs in terms of strength, resistance to corrosion and certain conditions prevailing in the environment, bolts and nuts are made of a wide variety of bolts materials. These are the high-performance metals as well as the special polymers. An example of this is stainless steel which provides a good combination of high strength and very good corrosion resistance. Although polymer is not as mechanically strong as stainless steel, it is a great alternative in situations where there is resistance to chemicals or electrical insulation required. The most used materials in the manufacturing of bolts are:

• Stainless Steel: It is better corrosive resistant, strong and reliable hence it suits humid, outside, and specialized mechanical tasks.
• Alloy Steel: has good tensile strength and fatigue, and is often used when bolts need heat treatment in order to obtain desired classes in their properties (e.g., $8.8$, $10.9$).
• Low Carbon Steel: This is affordable and very malleable; mostly it is used as general purpose, non-critical fasteners (e.g., ASTM A307).
• Medium Carbon Steel: A moderate element, which is stronger than low carbon steel and is normally quenched and tempered to be used in structures.
• Titanium: It has the best strength-to-weight ratio and excellent chloride corrosion resistance needed in aerospace and medical applications.
• Polymers such as Nylon: Due to their chemical resilience, a lack of magnetism, and electrical insulation.

The heat treatments and the application of different protective surface finishes or plating are majorly used to improve the performance of bolts and nuts, their durability, and appearance. Such finishes give the material stability, increase the service life of fastener, and guard the fasteners against the corrosion and rust. The most common options of finishing and coating and their advantages are listed below:

• Zinc Coating (Electroplating): This is the least expensive and most common type of coating, which offers fair resistance to overall corrosion and rust in dry or mild climate conditions.
• Galvanized (Hot Dip Galvanizing – HDG): The fastener is dipped in the melting zinc to form a thick coating, thus, providing better and lasting corrosion protection, usually with anti-seize properties, but with a higher initial capital outlay.
• Stainless (Passivation): This is a chemical treatment on stainless steel which improves its intrinsic resistance to corrosion by strengthening its passive chromium oxide layer. Its application is good in wet conditions and will be suitable in electrical or mechanical applications where permanence of integrity is of utmost importance.
• Black Oxide: This is the chemical process used in making the surface iron into magnetite that gives a deep black coloring to the surface to be used aesthetically. It does not provide much corrosion protection but it adds color, better grip as well as light deflection.