Steel is an essential material in the manufacture of products ranging from domestic appliances to aerospace components. As such, there is an extensive range of different steel grades, each of which is rated in terms of its various properties, such as strength and durability. As these properties differ from one grade to the next, so too do the steel numbers allocated to them.
Below is a list of the most commonly used steel numbers. While these are not always standardized across different regions, understanding the concept can provide a useful guide for the selection of appropriate steel grades for a given application.
Chinese Stainless Steels:
Cr17Ni2 (0Cr17Ni2) - Austenitic stainless steel
Cr18Ni11Ti (0Cr18Ni11Ti) - Austenitic stainless steel
Cr13 (1Cr13) - Martensitic stainless steel
Cr17 (1Cr17) - Ferritic stainless steel
Cr22Ni12 (2Cr22Ni12) - Austenitic stainless steel
Cr21Ni7 (3Cr21Ni7) - Austenitic stainless steel
Cr22 (3Cr22) - Martensitic stainless steel
Cr17Ni5 (4Cr17Ni5) - Austenitic stainless steel
Cr25Ni20 (4Cr25Ni20) - Austenitic stainless steel
Cr25Ni7 (4Cr25Ni7) - Austenitic stainless steel
Chinese Carbon Steels:
10 (10) - Plain carbon steel
11 (20) - Low alloy steel
15 (30) - Low alloy steel
20 (40) - Low alloy steel
35 (60) - Low alloy steel
45 (75) - Low alloy steel
50 (100) - Low alloy steel
60 (150) - Low alloy steel
70 (200) - Low alloy steel
80 (250) - Low alloy steel
90 (300) - Low alloy steel
95 (350) - Low alloy steel
Cr40Ni10Ti (40Ni10Ti) - High temperature structural steel
Chinese Alloy Steels:
20CrMo5 (20Cr5Mo) - Bearing steel
27SiMn (27SiMn) - Automobile structural steel
40Cr (40Cr) - Bearing steel
40CrMoV5 (40CrMoV5) - Automobile structural steel
45CrNiMoV (45CrNiMoV) - Bearing steel
50CrV (50CrVA) - Automobile structural steel
60CrMoV (60CrMoV) - Vehicle spring steel
70Cr3Mo (70Cr3Mo) - Automobile structural steel
80CrNiMoA (80CrNiMoA) - Bearing steel
85CrNiMoA (85CrNiMoA) - Bearing steel
Japanese Steels:
S10C (JIS S10C) - Plain carbon steel
S15C (JIS S15C) - Low alloy steel
S20C (JIS S20C) - Low alloy steel
S30C (JIS S30C) - Low alloy steel
S45C (JIS S45C) - Low alloy steel
56NiCrMoV7 (JIS 56NiCrMoV7) - Bearing steel
S13 (JIS S13) - Free cutting steel
SUS430 (JIS SUS430) - Ferritic stainless steel
SUS410 (JIS SUS410) - Martensitic stainless steel
SUS304 (JIS SUS304) - Austenitic stainless steel
SUS316 (JIS SUS316) - Austenitic stainless steel
United States Steels:
AISI 1020 (SAE 1020) - Plain carbon steel
AISI 1141 (SAE 1141) - Low alloy steel
AISI 4140 (SAE 4140) - Low alloy steel
AISI 4340 (SAE 4340) - Low alloy steel
AISI 52100 (SAE 52100) - Bearing steel
AISI 1045 (SAE 1045) - Medium carbon steel
AISI 4135 (SAE 4135) - Low alloy steel
AISI 4142 (SAE 4142) - Low alloy steel
AISI 4130 (SAE 4130) - Low alloy steel
AISI 1541 (SAE 1541) - Low alloy steel
311 (UNS S31100) - Martensitic stainless steel
316L (UNS S31600) - Austenitic stainless steel
321 (UNS S32100) - Austenitic stainless steel
Conclusion
This guide has highlighted a selection of commonly used steel numbers. With such vast differences between different grades, it is important to understand the implications of steel numbers when selecting an appropriate steel grade for a given application. Attention must be paid to the differences between national, regional and international standards, which are often not compatible with one another.
