Overview
| brand | Cantonese snail | Nominal diameter | four |
| length | ten | material quality | Carbon steel grade 4.8 |
| Applicable scope | Fasteners for mining machinery | producing area | Jiangmen |
| colour | silvery | Functional purpose | |
| Packaging specifications | two thousand and two hundred | model | M4 * 10 |
| Customized or not | no | Order number | Yue Luo-132 6870 6820-15284 |
| Standard type | Japanese standard | Delivery time | Within 48 hours |
| Performance level | Level 5.8 | Material grade | Stainless steel C450 |
Product Details
Bolt: Machine element, cylindrical threaded fastener with nut. A type of fastener consisting of a head and a screw (cylindrical body with external threads), which needs to be matched with a nut to securely connect two parts with through holes. This type of connection is called bolt connection. If the nut is unscrewed from the bolt, it can separate these two parts, so bolt connection is a detachable connection.
There are generally two types, one is made of iron, which is carbon steel. One type is stainless steel, and of course, there are also copper and aluminum nuts, but these are relatively rare to use. Copper is still somewhat useful, while aluminum nuts are rarely used.
"The process of nickel phosphorus plating on high-strength bolts consists of three parts:
The first part is the pre-treatment process, including precision and appearance inspection before high-strength bolt plating, manual oil removal, immersion oil removal, acid washing, electric activation, and flash nickel plating processes;
The second part is the chemical nickel plating process;
The third part is the post-processing process, including hydrogen displacement heat treatment, polishing, and finished product inspection. As follows:
Chemical composition inspection of bolts → accuracy and appearance inspection before bolt plating → manual oil removal → appearance inspection → immersion oil removal → hot water washing → cold water washing → acid washing → cold water washing → electric activation → cold water washing → flash nickel plating → cold water washing → deionized water washing → chemical nickel plating → deionized water washing → cold water washing → hydrogen drive → polishing → finished product inspection"
The commonly used screw materials in China include 45 # steel, 40Cr, ammoniated steel, 38CrMOAl, high-temperature alloys, etc. 1) 45 # steel is cheap and has good processing performance, but its wear and corrosion resistance are poor. Heat treatment: quenched and tempered HB220-270, high-frequency quenched HRC45-48. 2) The performance of 40Cr is better than that of 45 # steel, but it often requires a layer of chromium plating to improve its corrosion and wear resistance. However, there is a high requirement for the chromium plating layer. If the coating is too thin, it is easy to wear out, and if it is too thick, it is easy to peel off. After peeling off, it actually accelerates corrosion and has been less widely used. Heat treatment: quenched and tempered HB220-270, hard chromium plated HRC>553) nitrided steel, 38CrMoAl have excellent comprehensive properties and are widely used. Generally, the nitride layer reaches 0.4-0.6 millimeters. But this material has low resistance to hydrogen chloride corrosion and is relatively expensive. 4) High temperature alloy material is superior to other materials. It does not require coating and is mainly used for halogen-free screws in injection molding machines. This material has high oxidation and corrosion resistance, and is heat treated with hra55 ` 60
