What is A Stud in Mechanical Engineering – Types of Stud Fasteners


The position and forms of threads lead to various fasteners in mechanical engineering. We have talked about the basic fastening CNC parts including screws, rivets, bolts, etc. In this article, we are going to discuss what is a stud in the mechanical industry and what are the common types of stud fasteners.

What is A Stud in Mechanical Engineering?

The stud is a type of fastener with no head, only external threads on both ends. When connecting, one end must be screwed into the part with an internal thread hole, and the other end must pass through the part with a through-hole, and then screw on the nut to make the two parts firmly connected into a whole. This connection form is called stud connection, which is also a removable connection. It is mainly used when one of the connected parts is thick, requires a compact structure, or is not suitable for bolt connection due to frequent disassembly.


Stud vs bolt, what is the difference between stud and bolt?

A stud is defined as an externally threaded headless fastener, and a bolt is defined as a metal rod or pin for fastening objects together that usually has a head at one end and a screw thread at the other and is secured by a nut.


Studs often have threads on both ends and an unthreaded selection in the middle, while bolts are generally partially or fully threaded, the threads are often located on one end. In addition, studs do not have a head, while bolts typically do. 

Types of Stud Fasteners - Classification of Studs

Fastening studs can be classified into four common categories, there are a number of special stud variations for different purposes and applications. Learning about types of studs can help you select the best stud based on your needs. 

– Double End Studs: have equal-length threads on both ends to accommodate a nut, with an unthreaded portion in between the two threaded ends. Double-end threaded studs should be matched with nuts and washers for two connected parts with through holes, suitable for applications where torching from both ends is necessary or desirable. Dimensions can be defined in both metric and imperial systems with Unified National Coarse Pitch, Fine Pitch, etc.

– Tap End Studs: have a short thread on one end called tap end that is used for screwing into a tapped hole, and a longer thread on the other end called nut end that is used to accommodate a nut. Tap-end threaded studs are often applied in custom bolting requirements.

– Fully Threaded Studs: also known as continuous threaded studs, and referred to as a piece of threaded bar, are threaded from end to end, often used for fastening large parts together such as flange bolting with two nut supplied. Other purposes of fully threaded studs are to provide an adjustable part for structures and machines. Continuous threaded studs can be moved over a long distance along with the bar, which also generates a large force.

– Special Studs: there are also single-end threaded studs, locking studs, timber studs, welding studs, saddle studs, cripple studs, bonding studs, clinch studs and more types of special studs. 


One end of the welding stud is welded on the surface of the connected piece, and the other end (threaded end) passes through the connected piece with a through-hole, then put on the washer and screw on the nut to connect the two connected pieces as a whole.