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What Are the Nut and Screw Standards? (Part 2)

Mar. 23. 2020

Basic concepts of screws:

A screw is a screw. It is a part that is tightened step by step by using the principle of the bevel rotation and friction of the object. There are many hex head wood screw models and self-tapping screws. Hex head wood screw fastener suppliers to share with you.

Screw model:

The screw models are actually differentiated in detail according to different national standards. The metric thread is in millimeters of Wie. Its thread tip angle is 60 degrees. The American and British threads are in inches. The tip angle of the thread is also 60 degrees, while the tip angle of the inch threads is 55 degrees. The screws include self-tapping screws, self-drilling screws and so on.

Hex Head Wood Screw

Hex Head Wood Screw

New standard for screw models:

There are old standards and new standards for screw types. The old standards are basically no longer used by manufacturers, and all of them are new standards. At present, the most used on the market is GB5780, GB5781, GB5782, GB5783, GB5784. Among them, GB5780 is a hexagon head thick rod and half tooth screw, which is a high-precision C-class product, and GB5781 is a hexagon head full-screw, and the accuracy level is also C-class. The difference between the new standard and the old standard is that the products of the M8, M10, M12, M14, M22 series have differences in the width of the opposite sides. In addition to the above series M22, the head of the M8, M10, M12, and 14 is 1 mm smaller than the old standard, and the new product of the M22 series is 2 mm larger than the old standard, although the difference is not significant , But there is still a large gap with the fastness of fastening. Specifications: B spherical cylindrical head, C cylindrical head, FK countersunk head, H hexagon head, HW hexagon head with washer, O half countersunk head, P flat element head, PW flat element head with washer, T large flat head, V mushroom head.
Self-tapping screw model:

Self-tapping screws. Self-tapping screws are parts that are fastened between metal or non-metallic materials. They are mostly used for direct connection of thin metal plates. It has a very high anti-loose ability and can be loaded and unloaded. Self-tapping screws have more than 100 specifications including round head, flat head, half countersunk head, countersunk head, hexagon head, pan head, flat top and so on.

There are many types of screws, and it is difficult for general sellers to sell them all year round, so consumers must know the size and model of the screws they need when buying screws. Screws are often used on non-metal or relatively soft metal, and can be firmly fixed on the material. It does not need to be used with a nut, which saves costs and improves work efficiency. The types of screws introduced above are not comprehensive. If consumers have any questions, please feel free to contact us.