Thick tooth thread
The so-called thick teeth actually refer to standard threads. Without special instructions, the fasteners such as stainless steel screws we usually buy are thick teeth.
Coarse tooth threads are characterized by high strength, good interchangeability, and standard control. Generally speaking, thick teeth should be the best choice.
Compared with the fine teeth thread, due to the large screw spacing, the thread lifting angle is also large, and the self-locking performance is poor. In the vibration environment, anti-loose washer, self-locking devices, etc. need to be installed.; the advantages are that it is convenient to disassemble and assemble and assemble, and the matching standard parts are complete, and easy to interchange;
There is no need to mark the pitch when marking coarse tooth threads, such as M8, M12-6H, M16-7H, etc., which is mainly used for connection threads.
Fine tooth threads
On the contrary, fine teeth and coarse teeth are stipulated to supplement the special use requirements that coarse teeth threads cannot meet. Fine tooth threads also have a series of pitches, and the pitch of fine teeth are smaller. Therefore, they are characterized by more self-locking, anti-loose, and more teeth, which can reduce the leakage effect and achieve the sealing effect. In some precision occasions, fine-toothed stainless steel screws are more convenient to control and adjust accurately.
The disadvantage is that the tensile value is low, the strength is lower than that of the thick teeth, and the thread is easy to damage. It is not recommended to disassemble and install it many times. The fasteners such as the matching nuts may be as accurate, and the size is slightly wrong, which is easy to cause the screw nut to be damaged at the same time.
Fine tooth threads are mainly used in metric pipe fittings, mechanical transmission parts, thin-walled parts with insufficient strength, interior parts subject to space restrictions, and shafts with high self-locking requirements. When labeling fine tooth threads, the pitch must be marked to show the difference from the thick tooth thread.
How to choose thick teeth and fine tooth threads?
Both thick tooth threads and thin tooth thread screws are used for fastening.
Thin tooth screws are generally used to lock thin-walled parts and parts with high requirements for vibration protection. The self-locking performance of fine teeth threads is good, so the anti-vibration and anti-loose ability is strong. However, due to the shallow depth of threaded teeth, the ability to withstand greater tension is worse than that of thick teeth.
When anti-loose measures are not taken, the anti-loose effect of fine tooth threads is better than that of thick teeth. It is generally used in thin-walled parts and parts with high anti-vibration requirements.
When adjusting, fine tooth threads have more advantages. Disadvantages of fine tooth threads: It is not suitable for application in materials with excessive thickness and poor strength. When the tightening force is large, it is easy to slip.
