fastener-material-and-strength
3. Material: The most common materials are: carbon steel, stainless steel, stainless iron, copper, aluminum, etc.
Carbon steel is divided into low carbon steel (such as C1008 / C1010 / C1015 / C1018 / C1022), medium carbon steel (such as C1035), high carbon steel (C1045 / C1050), and alloy steel (SCM435 / 10B21 / 40Cr).
Generally, C1008 is made of ordinary grade products, such as 4.8-level screws and ordinary-grade nuts; C1015 is generally used as ring screws; C1018 is generally used as machine screws, of course, it is also used as self-tapping screws; C1022 is generally used as self-tapping screws ; C1035 hits 8.8 screws; C1045 / 10B21 / 40Cr hits 10.9 screws; 40Cr / SCM435 hits 12.9 screws.
Stainless steel has SS302 / SS304 / SS316 as the most common. Of course, there are also a lot of SS201 products, even products with lower nickel content. We call them non-authentic stainless steel products; the appearance looks similar to stainless steel, but the corrosion resistance is much different.
4. Strength grade: The strength grade mainly refers to carbon steel fasteners.
Common strength grades for carbon steel screws are: 4.8, 5.8, 6.8, 8.8, 10.9, and 12.9. The corresponding nuts are: 4th, 6th, 8th, 10th, and 12th.
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 be quenched and tempered.
5. Surface treatment: The surface treatment is mainly to increase the anti-corrosion performance, and some of them also take into account the color, so it is mainly for carbon steel products, and generally requires surface treatment.
Common surface treatments are: blackening, galvanizing, copper plating, nickel plating, chrome plating, silver plating, gold plating, Dacromet, hot-dip zinc, etc .;
There are many types of galvanization, including blue and white zinc, blue zinc, white zinc, yellow zinc, black zinc, and green zinc. At the same time, it is also environmentally friendly and non-environmental. Each type of plating has multiple coating thicknesses to meet different requirements. Salt spray test effect.