Stud bolts are also called double-head screws or studs. The fixed link function used to connect the machine. The stud bolts have threads on both ends, and the middle screw is thick or thin. Generally used in mining machinery, bridges, automobiles, motorcycles, boiler steel structures, crane towers, large-span steel structures and large buildings, etc.
Bolts specifically refer to screws with larger diameters, and can also have no heads, such as stud bolts. Generally, it is not called a "stud bolt" but a "double stud". The most commonly used form of double-ended studs has threads at both ends and a polished rod in the middle.
The most typical use: anchor bolts, or places similar to anchor bolts, thick connections, when ordinary bolts cannot be achieved.
The main purpose
1. It is used in large-scale equipment that requires installation accessories, such as sight glasses, mechanical seal seats, and deceleration racks. At this time, stud bolts are used, one end is screwed into the main body, and the other end is fitted with a nut after the attachment is installed. Since the attachment is often disassembled, the thread will be worn or damaged. It is very convenient to use stud replacement.
2. When the thickness of the connecting body is very large and the bolt length is very long, stud bolts will be used.
3. Used to connect thick plates and places where it is inconvenient to use hexagon bolts, such as concrete roof truss, roof beam suspension monorail beam suspension, etc.
In actual work, external loads such as vibration, change, and high-temperature creep of the material 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 thread connection It will relax and fail. Therefore, it is necessary to prevent loosening, otherwise it will affect normal work and cause accidents.
Stud bolt function: generally used for mining machinery, bridges, automobiles, motorcycles, boiler steel structures, crane towers, large-span steel structures and large buildings.
Introduction to Stud Bolts Stud bolts save time and cost. The structure of all stud bolts does not require drilling, punching, threading, riveting, screwing and finishing steps, and continuously expands the application potential of structural design, high current and comparison Small penetration. Therefore, it can be welded to very thin plates. The work piece for stud welding must be welded from one side. It can be welded in all positions and can be restricted with the help of an extender on the vertical partition. Because it is welded in a short time and there is little deformation after welding, no trimming is required. Because the welded structure does not require drilling, it will not cause leakage. The joint can reach very high strength, that is, the joint strength of stud welding is greater than the strength of the stud itself.
How to install studs is economical. The advantage of other welding methods lies in the welding power. For mass-produced workpieces, standard studs are low-cost. There are many types of equipment and welding guns, and the purchase cost of equipment is relatively low. According to the product, it can be made into a multi-station automatic welding machine, or a high-precision gantry CNC automatic welding machine. Stud welding has a higher quality reproduction rate and a smaller rejection rate. However, in the application of stud welding, attention should be paid to other fusion welding, which has certain restrictions on the carbon content in steel. For structural steel studs, weld according to the weldability of the recommended stud material and base metal combination, otherwise the stud There will be infusibility between it and the base metal. The combination of stud materials and base materials outside the recommended range shall be tested to determine the weldability and the product design requirements of anchor bolts for relevant inspection and evaluation possibilities.
Stud bolts generally need to undergo 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, and communications. 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.
Basic knowledge and maintenance
The production of stud bolts requires fixed equipment and machine tool processing. Of course, the processing procedure is relatively simple. There are mainly the following procedures: First, the material needs to be drawn. The drawing is to straighten the distorted material with a drawing machine. After this process, the next process can be carried out. The next process is to use a cutting machine to cut the straightened long material into the length required by the customer according to the customer's requirements. This completes the second process, and the third process is Put the cut short material on the thread rolling machine to roll out the thread; here the ordinary stud bolts are processed, of course, if other requirements are required, other processes are needed.
Generally known bolts refer to screws with larger diameters. According to this statement, screws have a much smaller diameter than bolts. Stud bolts have no heads, and some are called studs. Both ends of the stud bolt are threaded, without thread in the middle, and a polished rod in the middle. Stud bolts are used on large equipment such as reduction racks. In actual use, the external load will vibrate and the influence of temperature will cause the friction to become smaller, and the threaded connection will relax and fail over time. Therefore, it is necessary to do the maintenance of the stud bolts in normal times. Stud bolts or anchor bolts will have problems under the action of mechanical friction for a long time. When there is a problem, the engine oil pan should be removed, and the use of the engine bearing bushes should be carefully checked, and the gap between the bearing bushes should be checked. Whether it is too large, if the gap is too large, replace it in time. When replacing the stud bolts, also replace the connecting rod bolts. Some large equipment such as nail making machines should be stopped in time for inspection if they find that the engine is not running very stable or there is abnormal noise during normal operation, so as to avoid bigger problems.
During each maintenance, the newly replaced studs and other newly replaced accessories must be inspected. The focus of the inspection is on the head and guide part of the stud, and the thread must be strictly checked for each part. No cracks or dents, but also check the tooth shape of the stud to see if there is any change. Whether there is any abnormality in the pitch, if there is any abnormality, it must not be used again. The torque wrench should be used when installing the connecting rod cover. Must be tightened in accordance with the prescribed standards, the torque must not be too large or too small, but also pay attention to choose the stud bolts and studs of the supporting manufacturer.