Double-end stud refers to threaded fasteners with separate threads. Widely distributed power, chemical, oil refining, valves, railways, axial, steel structures, auto and motorcycle parts, machinery, boiler steel structures, crane towers, large-span steel structures and large buildings.

The diameter, length and quantity of stud bolts should meet the requirements. The type and material of stud bolts are determined by the grade. There are two commonly used stud bolts (also known as full thread studs), and the threads are divided into coarse and fine threads.

Coarse common thread is expressed by M and nominal diameter, fine common thread is expressed by M and nominal diameter × pitch. The fastener standard stipulates that M36 bolts use coarse thread.
For diameters of M36 and above, fine thread can be used, and the pitch is 3. bm=1d double-ended studs are generally used for the connection between two steel connected parts; bm=1.25d and bm=1.5d double-ended studs are generally used for cast iron to be connected and steel to be connected The connection between; bm=2d double-ended studs are generally used for the connection between the aluminum alloy to be connected and the steel to be connected.

The former connector has internal threaded holes, and the latter connector has through holes. The threads at both ends of the equal-length double-ended studs need to be matched with nuts and washers for two to be connected with through holes.

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

Representation format:

The thread specification d=M12, the nominal length L=80mm, and the performance level is 4.8. The complete mark of the equal length stud bolt is: GB 901 M12×80 [1]

Product examples:

Double-ended studs generally require surface treatment. There are many types of bolt surface treatments. Generally, electroplating, blackening, oxidation, phosphating, and non-electrolytic zinc flake coating are commonly used.

However,electroplated fasteners occupies a large proportion in the actual use of fasteners. Especially in industries and fields such as automobiles, tractors, home appliances, instrumentation, aerospace, communications, etc.
For extensive. However, for threaded fasteners, not only a certain anti-corrosion ability is required in use, but also the interchangeability of threads must be guaranteed, which can also be referred to as screwability here.

In order to meet the dual use performance of “anti-corrosion” and “interchangeability” required by threaded fasteners at the same time, it is very necessary to formulate special plating standards.

Main applicationsedit:

When the main body is a large-scale equipment, it needs to install accessories, such as sight glass, mechanical seal seat, reduction frame, etc. The stud bolts used at this time, one end is screwed into the main body, and the other end is fitted with a nut after the accessories are installed.

Because the accessories are often disassembled, when the main body and the accessories are directly connected by bolts, the main body’s threads will wear out or damage over time, and the use of stud bolts will change Very convenient.

When the thickness of the connecting body is very large and the bolt length is very long, stud bolts will be used. The purpose of anti-loosening of stud bolt connection In actual work, the external load has vibration, change, high temperature creep of the material, etc., which will reduce the friction.

The positive pressure in the thread pair disappears at a certain moment and the friction is zero, which makes the thread connection loose , If repeated action, the threaded connection will be loose andInvalidate. Therefore, it is necessary to prevent loosening, otherwise it will affect normal work and cause accidents.