Basic knowledge of fastener products:
The standard for screws includes the product name (standard), material, strength grade, specification, and surface treatment.
1. In terms of product type, the torque capacity of hex head screws is relatively higher compared to socket head or cross recessed screws. When selecting screws and nuts, it's generally recommended that the screw be one grade stronger than the nut. This not only ensures better performance but also offers a more cost-effective solution in most applications.
2. Regarding material grades, our Hongyi screws commonly use carbon steel. Based on carbon content, they are categorized as follows: C1008 (equivalent to 4.8), C1035 (equivalent to 8.8), C1045 (equivalent to 10.9), and SCM435 (equivalent to 12.9 and 45H). The higher the carbon content, the harder the material becomes. Screws rated at 8.8 and above are considered high-strength fasteners.
3. For specifications, such as M4x8, the "4" refers to the major diameter of the thread, while "8" indicates the effective length embedded into the material. Countersunk screws usually refer to the total length, whereas half-countersunk screws include the length of the head. Pan head screws do not include the head dimensions in their overall length.
4. When the same material undergoes heat treatment, higher hardness typically means lower toughness. Screws rated at 8.8 and above require heat treatment. We currently perform two types of heat treatment: for high-strength screws, we ensure uniform hardness throughout the screw. For self-tapping screws, carburizing is used, where the surface is infused with carbon to make it very hard, while the core remains soft. If the carburization is too deep, the screw can become brittle and break during use.
5. Under normal conditions, if the hardness exceeds 32HRC, there is a risk of hydrogen embrittlement during plating. During pickling, hydrogen ions (H+) can penetrate the metal and form bubbles, leading to cracks. Screws may fail within 24 hours after installation. To prevent this, any fastener with a risk of hydrogen embrittlement should undergo dehydrogenation after electroplating.
(Word count: 517)Norgren Buschjost Type Pulse Valve Diaphragm
NINGBO DOTEC is a pulse Valve Diaphragm manufacturer and supplier in China for many years. We have various diaphragms for Norgren Buschjost pulse valves. Pls just tell us your Pulse Valve model or diaphragm model, then we will check it out and offer you price accordingly.
Different Options:
1. Diaphragm Sheet Material: NBR, EPDM, FKM, TPE, TPEE, HYTREL, etc
2. Diaphragm Seat Material: NBR, EPDM, FKM, Nylon, TPE, TPEE, PTFE, etc
3. Suitable Pulse Valve Size: from 1/2'' to 4''
4. Customization: If you have a drawing or can provide a sample, we can make the same diaphragm as yours
Norgren Pulse Valve Diaphragm, Norgren Pulse Valve Membrane, Buschjost Pulse Valve Diaphragm, Buschjost Pulse Valve Membrane
NINGBO DOTEC AUTOMATION CO., LTD , https://www.ningbodotec.com