Thread Pitch is an important dimension associated with a Bolt. In imperial system, the thread pitch of the bolt is determined by the number of threads in one inch. In metric system, the distance between two adjacent threads in millimeters is considered as the Thread Pitch. If two parts must be joined together, then the first step is to drill a hole in the objects. The hole can be tapped or normal. If the hole is a tapped hole, then the bolt can be simply threaded into the hole (provided the pitch of the hole and the bolt is the same) without the need for a nut to secure the bolt. If it is a normal hole, then you have to use a washer and nut to properly secure the bolt. The material used in the manufacturing of the bolts will determine its strength, applications, corrosion resistance etc. There are several materials of Bolts and some of the popular ones are: A Bolt is a cylindrical object with a hexagonal (sometimes square) head on one end and threads (fully or partially) on the other end. A Nut is the counterpart of the Bolt and it is hexagonal (sometimes square) object with threads on the inside. The pitch of the threads on the bolt and nut should be the same for securing them properly. The diameter of the Bolt is the actual size of the bolt and it is measured across the bolt shank or the threaded area. The body length of the bolt is measured from the tip of the bolt to the point where the shank meets the head. If the bolt is partially threaded, then the thread length can also be measured.

IMPORTANT NOTE: People often confuse between the size of the bolt and the size of the bolt head. When we say ‘size of the bolt’, it usually means the diameter of the bolt’s shank. The size of the bolt head is used to determine the size of the wrench to tighten or loosen the bolt. Grade or ClassEasyMech SS Hex Nut are internally threaded and have a hex drive for nearly all general applications. It is most commonly used nut for wide range applications. Hex Nuts are used in any application with a mating male threaded machine bolt or screw. Can be used with any fastener with a machine screw thread. Hex Nuts are used with compatible sized bolts and washers.

Before looking at the Bolt Size Chart, let us first try to understand different proportions and dimensions associated with a bolt. The following image shows a typical hex bolt with all the important dimensions marked on it.Consider a Class 10.9 Bolt. Here, this bolt has a tensile strength of 1,000MPa (145,000PSi) and a yield strength of 900MPa (130,000PSi).

Stainless Steel: One of the toughest bolt materials with very good corrosion resistance. As a result, stainless steel bolts are often used in industries, automobiles, ships (and other marine equipment) and outdoor objects in general. They are slightly expensive than the Zinc plated counterparts. The Bolt Body consists of the main shank with full or partial threads. Bolt Body can have important dimensions. They are: Another important specification associated with bolts is its grade (imperial) or class (metric), which determines the tensile strength of the bolt. The tensile strength of a bolt is the maximum stress / stretch it can handle before it breaks.In metric system, the strength of the bolt is determined using its class number, which is also printed on the head of the bolt. Higher the class number, greater is the strength of the bolt. If the number is followed by another number (for example, 10.9), then the second number represents the yield strength of the bolt, which determines the stress it can handle before it cannot return to its original shape without damage. Zinc-Plated Steel: It is one of the popular and commonly used bolt materials for general purpose applications, usually indoor. Depending on the type of manufacturing, the color of the bolt may be bluish or yellowish tint. It is a low carbon steel with a Zinc coating that provides moderate corrosion resistance. They are very cheap to manufacture as well.

As Bolts and Nuts are one of the commonly used fasteners, there are different types of bolts for different types of applications. Some of the more common and popular types of bolts are: The combination of a bolt, a nut and a washer can be used to secure two objects and the best part is the joint is temporary in the sense you can remove it anytime just by loosening the nut. In USCS imperial system, the bolt’s tensile strength is represented using ‘grade marks’ on the top of the head. The ‘grade marks’ are nothing but radial lines and more the number of lines on the head of the bolt, greater is the strength of the bolt. Brass / Bronze: These types of bolts have a natural resistance to corrosion as they are alloys of copper. They are generally expensive than other bolt materials and as a result they are often used in arts and decorative pieces. An important point about the dimension of the hole to be drilled is it must of the same diameter as the diameter of the bolt or slightly larger than that. Bolt MaterialsThe head of the bolt is usually hexagonal shape (sometimes square or circular) and is used to tighten or loosen the bolt. The size of the head is dependent on the shank’s nominal diameter.