Introduction to fastener processing and cold upsetting process

I. Introduction to cold forging process
The cold upset forging process is a less-cut metal pressure processing process. It is a method of processing the required parts or blanks by utilizing the plastic deformation of the metal under external force and by means of the mold to redistribute and transfer the metal volume.
Characteristics of cold upsetting process:
1. Cold weather is carried out under normal temperature conditions. Cold upsetting can improve the mechanical properties of metal parts.
2. Cold upset forging can increase material interest rates. It is a pressure processing method based on plastic deformation, which can achieve less cutting or no cutting. The general material utilization rate is above 85%, and the highest is over 99%.
3. Can increase production efficiency. The time and process of deformation of metal products are relatively short, especially in the processing of parts on a multi-station forming machine, which can greatly improve productivity.
4. The cold upsetting process can improve the surface roughness of the product and ensure the accuracy of the product.

Second, the requirements of raw materials for cold forging process
1. The chemical composition and mechanical properties of raw materials should comply with relevant standards.
2. The raw material must be subjected to spheroidizing annealing treatment, and the metallographic structure of the material is spherical pearlite 4-6.
3. The hardness of the raw materials, in order to minimize the tendency of the material to crack, improve the service life of the mold also requires the cold drawing material to have as low a hardness as possible to improve the plasticity. Generally, the hardness of raw materials is required to be HB110~170 (HRB62-88).
4. The accuracy of the cold-drawing material should generally be determined according to the specific requirements of the product and the process conditions. Generally speaking, the requirements for the diameter reduction and the shrinkage dimension are lower.
5. The surface quality of the cold-drawn material requires that the lubricating film be dull and dark, and the surface must be free from scratches, folds, cracks, napped, rust, scale and pits.
6. It is required that the total thickness of the decarburized layer in the direction of the cold drawing material does not exceed 1-1.5% of the diameter of the raw material (depending on the requirements of each manufacturer).
7. In order to ensure the cutting quality during cold forming, the cold drawing material is required to have a hard surface and a soft core.
8. The cold drawing material should be subjected to the cold upsetting test, and the lower the sensitivity of the material to the cold work hardening, the better, so as to reduce the deformation resistance due to cold work hardening during the deformation process.

Third, the fastener processing technology brief
Fasteners are mainly divided into two types of manure: one is threaded fasteners; the other is non-threaded fasteners or couplings. This is only a brief description of threaded fasteners.
1. The thread type fastener processing process is generally composed of cutting, cold heading, or cold extrusion, cutting, thread processing, heat treatment, surface treatment and other production processes.
The material rebuilding process is generally:
Picklingâ†’drawingâ†’annealingâ†’phosphating saponificationâ†’drawingâ†’(spheroidizing phosphating)
There are several conditions for the cold-added process of thread-type fasteners:
8.8 grade thread fasteners processing process head â†’ cleaning â†’ æ“ thread â†’ cleaning â†’ surface treatment â†’ packaging threaded fasteners below 8.8 grade product processing flow head â†’ cleaning â†’ cutting â†’ heat treatment â†’ wearing æ“ thread â†’ cleaning â†’ Surface treatmentâ†’Packing 8.8.10.9 thread fasteners Product processing flow headâ†’cleaningâ†’cuttingâ†’twisting threadâ†’heat treatmentâ†’cleaningâ†’surface treatmentâ†’packaging 10.9-12.9 thread fasteners product processing flow headâ†’cleaningâ†’heat treatmentâ†’cutting â†’Rolling threadâ†’Cleaningâ†’Nondestructive testingâ†’Cleaningâ†’Surface treatmentâ†’Packaging 2. Threaded fasteners commonly used materials Thread fasteners commonly used materials are shown in Table 1 (including domestic and foreign materials comparison)

Centrifuge Tube Rack

At present, in the process of isolation and preparation of various stem cells from various tissue sources, Centrifuge Tubes with a volume of 15ml and 50ml are used.
It is one of the low-value consumables with high usage rate. It is generally installed on a dry foam rack with the package or in bulk. When used, it is taken out by the operator and placed on the plastic centrifuge tube rack in the ultra-clean workbench. The common centrifuge tube rack can only make the centrifuge tube stand upright. When transferring liquid or needing centrifugation, the operator should hold the centrifuge tube in the left and the night gun or aspirator in the right. If it is necessary to transfer a large amount of liquid reagents or perform gradient centrifugation operations, such as density gradient centrifugation to separate mononuclear cells, the operator needs to hold the centrifuge tube with the right hand for a long time and tilt the centrifuge tube, which often causes the operator's wrist joint pain. At the same time, it will also affect the liquid superposition effect, which will easily lead to the mixing of liquids of different densities, resulting in the failure of the experiment.

centrifuge tube rack bulk,tube rack for centrifuge,rack for centrifuge tube

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