What parameters should be provided for custom long bolt screws?

There are often customers who do not know what parameters need to be provided to produce long bolt screws when they customize them. Now let’s talk about what parameters need to be provided for long bolt screws customization.

1. Size. Dimensions include thread diameter, thread length, screw length, rod diameter, head diameter, head thickness, etc., as well as tolerance requirements. Some people are confused when they see the length of thread and the length of the screw in the size, isn’t this the same? It’s different. Because the length of long bolt screws is generally more than 100mm, some customers do not need full thread, as long as half thread, in this case, the need to provide the length of thread.

2, material. Different materials have different mechanical properties, as well as their own characteristics. And different materials will also affect the production process. So 304 stainless steel is more suitable for cold heading production, 303 stainless steel is more suitable for automotive processing.

3. Surface treatment. There are many kinds of screw surface treatment, such as vacuum electroplating, hardening, galvanizing, anodic oxidation, micro-arc oxidation, nickel plating, gold plating, copper plating, passivation, high temperature blackening, electrophoresis, zinc-Nickel alloy, Dacromet and so on. Some surface treatments are only suitable for certain materials, and different surface treatments have different salt spray test times.

4. Shape. You need to specify the head shape of the long bolt screws, such as flat head, cap head, pan head, etc. What groove type, if cross, slotted, slotted/phillips, torx, hexagon socketetc. What is the thread, such as machine, self tapping flat tail, self tapping tip tail and so on.

5. Other requirements. For example, long bolt screws is required to be anti-loose, anti-slip, anti-theft, packaging requirements, and so on.