The difference between cylindrical pins and fixed pins

　　Difference between cylindrical pins and fixed pins

　　In machinery, cylindrical pins are mainly used for assembly and positioning, and can also be used as overload shear connections in connecting and loosening safety devices. There are many types of pins, including: cylindrical pins, tapered pins, pins with holes, cotter pins, and safety pins, etc. The basic forms are cylindrical pins and tapered pins, which should be selected according to the type of pin and work requirements during operation. Pins are still very common in daily life, so how to distinguish between cylindrical pins and tapered pins? This article mainly explains this for you.

　　Cylindrical pins can be used for positioning, power and torque transmission, and as a disconnect protection in safety devices. There are many types of pins, including tapered pins, internal threaded tapered pins, cylindrical pins, internal threaded cylindrical pins, split tapered pins, threaded cylindrical pins, pins with holes, and tail pins, etc. Each type of pin has different specifications. The most common pins can be divided into two categories: cylindrical pins and tapered pins.

　　A cylindrical pin is a locating pin, the main advantage is that it is subjected to better force. It is used to fix the relative positions between parts and plays an important auxiliary role in combined processing and assembly. Cylindrical pins require higher tolerance accuracy; otherwise, if the fit is not good, the pin is easily lost.

　　The type of cylindrical pin is selected according to its working requirements. The diameter of the pin used for connection can be determined empirically according to the structural characteristics of the connection, and the strength should be checked if necessary. The directionality of the locating pin can be determined according to the structure. The length of the pin in each connector is approximately 1 to 2 times its diameter.

　　The commonly used material for pins is 35 or 45 steel. The materials for safety pins are 35, 45, 50, T8A, T10A, etc., and the hardness after heat treatment is 30~36HRC. The materials for pin sleeves can be 45, 35SiMn, 40Cr, etc., and the hardness after heat treatment is 40~50HRC.

　　Difference between cylindrical pins and fixed pins

　　1. Different processing. Cylindrical pins can be pre-processed, and tapered pins are usually matched.

　　2. Elastic cylindrical pins are often used in situations that require precise positioning (pre-machining), and tapered pins are often used for frequent disassembly.

　　3. Elastic cylindrical pins can resist shearing, tapered pins are often used for positioning.

　　Elastic cylindrical pins are fixed in the hinge hole, with a small interference fit, and can withstand a smaller load. In order to ensure positioning accuracy and connection tightness, frequent disassembly should be avoided. It is mainly used for positioning and also used as a connecting pin and safety pin.

　　The taper of the tapered pin is 1:50. It has good self-locking performance, high positioning accuracy, and easy installation. Repeated disassembly has little effect on positioning accuracy. It is mainly used for positioning and can also be used as a connecting pin. The pin hole needs to be reamed.

　　The elastic cylindrical pin is elastic. After being inserted into the pin hole, it fits tightly against the hole wall and is not easy to loosen. The pin hole accuracy is low. Interchangeable holes can be repeatedly disassembled. Suitable for occasions with impact and vibration, it can replace some cotter pins, cylindrical pins, pins or tapered pins.