1.The parameters that need to be marked to describe the fasteners are: product name (standard), specification, material, strength grade, and surface treatment.
2. Product name (standard): Note: For screws without standard, which are non-standard parts, drawings are required.
For example, DIN912, the Chinese name is: hexagon socket head screw, which is the product name.
3.The most influential standards in the world are: German Standard (DIN), International Standard (ISO), Chinese National Standard (GB), American Standard (ANSI), Japanese Standard (JIS).
4.Material: The most common materials are: carbon steel, stainless steel, stainless iron, copper, aluminum, etc.
Strength grade: The strength grade mainly refers to carbon steel fasteners.
The common strength grades of carbon steel screws are: 4.8, 5.8, 6.8, 8.8, 10.9, and 12.9. The nuts are correspondingly: level 4, level 6, level 8, level 10, and level 12.
Generally, screws below grade 8.8 are called ordinary screws, while screws above grade 8.8 (including grade 8.8) are high-strength screws. The difference is that high-strength screws need to undergo quenching and tempering heat treatment.
5.Surface treatment: Surface treatment is mainly to increase the anti-corrosion performance, but also partly takes into account the color, so it is mainly for carbon steel products, which generally require surface treatment.
Common surface treatments are: blackening, galvanizing, copper plating, nickel plating, chrome plating, silver plating, gold plating, dacromet, hot dip galvanizing, etc.;
There are many types of zinc plating, including blue and white zinc, blue zinc, white zinc, yellow zinc, black zinc, green zinc, etc., and they are also divided into environmental protection and non-environmental protection. Each type of plating has a variety of coating thicknesses to meet different requirements.
Post time: Sep-14-2021