Introduction to Dimensions and Classification of Outer Hexagonal Bolts

2023-10-27

When it comes to outer hexagonal bolts, I believe everyone will not be particularly unfamiliar. We usually call it an external hexagonal screw, an external hexagonal screw. Many people may ask why we call an external hexagonal bolt? Because the outer hexagonal bolt is a bolt with a hexagonal head, the head and lower part of the outer hexagonal bolt form a fixed accessory. Outer hexagonal bolts can be divided into two types based on material: iron bolts and stainless steel bolts. Below, we will introduce the size and classification of external hexagonal bolts, hoping to deepen your understanding of external hexagonal bolts.

1、 Introduction to Outer Hexagonal Bolts

Hexagonal bolts refer to hexagonal head bolts (partially threaded) - Class C and hexagonal head bolts (fully threaded) - Class C, also known as hexagonal head bolts (rough) rough hexagonal head bolts or black iron screws. Common standards can be found in SH3404, HG20613, HG20634, etc. Hexagonal bolts refer to fasteners composed of the head and screw, which are divided into iron bolts and stainless steel bolts according to their material. Iron is divided into grade 4.8 bolts and grade 8.8 bolts. Stainless steel bolts are made of stainless steel SUS201 bolts, SUS304 bolts, and SUS316 bolts.

2、 Standard dimensions of external hexagonal bolts

The standard for external hexagonal bolts is DIN, ANSI, BS, GB, and other materials. Stainless steel or carbon steel or specified diameters are generally 5mm to 20mm, and 1/4 "to 3/4". Length: 8mm~200mm, 5/16 ″~8 ″. Threads: Metric, coarse, fine, and imperial, with mechanical properties of 4.8, 5.8, 6.8, 8.8, 9.8, 10.9, and 12.9. The surface treatment methods are generally natural color, zinc plating, blackening, and nickel plating. The outer hexagonal bolt M6 * 30 can accurately describe a bolt with a diameter of 6MM and a thread length of 30MM.

3、 Classification of outer hexagonal bolts

1. According to the stress mode of the connection, there are ordinary and reamed holes. The bolts used for reaming holes should match the size of the holes and be used when subjected to lateral forces.

2. According to the shape of the head, there are hexagonal heads, round heads, square heads, countersunk heads, etc. Generally, countersunk heads are used in places where the surface is required to be smooth and not protruding after connection, because countersunk heads can be screwed into the parts. Round heads can also be screwed into the parts. The tightening force of square heads can be larger, but the size is large. Hexagonal heads are the most commonly used.

In addition, in order to meet the needs of locking after installation, there are holes in the head and the rod, which can prevent the bolts from loosening when subjected to vibration. Some bolts with no threads on the bare rod need to be made thin, called slim waist bolts. This type of bolt is beneficial for connection under variable forces. There are specialized high-strength bolts on the steel structure. The head will be larger and the size will also change. Additionally, there are special uses for T-groove bolts, which are most commonly used in machine tool fixtures. They have a special shape and require cutting off both sides of the head. Anchor bolts are used for connecting and fixing machines to the ground, and there are many different shapes, such as U-bolts, as mentioned earlier. There are also specialized studs for welding, with threads on one end and no threads on the other end, which can be welded to the parts while directly tightening the nuts on the other side.

Of course, in our daily use, there will definitely be some malfunctions. How should we deal with the failure of the outer hexagonal bolt? Generally speaking, bolts in machines like diesel engines are recommended for one-time use, as multiple uses may lead to accidents. However, some units may also encounter regular and regular replacement of outer hexagonal bolts, but still encounter machine malfunctions. Therefore, it is necessary to consider whether excessive force is applied during installation. Secondly, when using external hexagonal bolts in daily life, they should be rinsed and no residue should be left on the surface of the external hexagonal bolts. The stacking method should be reasonable, and only by carefully maintaining the external hexagonal bolts can they play their maximum role during use. That's all for today's introduction of the relevant knowledge on the size classification of outer hexagonal bolts. I hope it can help everyone.

What factors affect the quality of stainless steel non-standard screws? How can I buy high-quality stainless steel combination screws? back