What does SS400 mean?

SS400 is a JIS general structural rolled steel. 'SS' stands for Steel-Structural and '400' is the minimum tensile strength in MPa (400-510 MPa). It is one of the most common low-cost structural steels.

What is the difference between SUS304 and SUS316?

Both are austenitic stainless steels. SUS316 adds about 2-3% molybdenum, giving it markedly better resistance to pitting and chloride corrosion, which makes it preferred for marine, chemical and medical environments. SUS304 is cheaper and adequate for most general use.

What is duralumin (A2017, A7075)?

Duralumin refers to high-strength heat-treatable aluminum alloys. A2017 (duralumin) is an Al-Cu alloy; A7075 (extra-super duralumin) is an Al-Zn-Mg-Cu alloy with the highest strength of common aluminum, used in aircraft and high-load parts. Their corrosion resistance is lower than Al-Mg alloys such as A5052.

Why are the property values approximate?

Mechanical properties depend strongly on heat treatment (e.g. annealed, normalized, quenched and tempered), product thickness, temper and the specific standard edition. The values here are representative; for design always consult the current JIS/ASTM standard and the mill certificate of the actual material.

How do JIS grades relate to AISI/ASTM and EN numbers?

Many JIS grades have near-equivalents in other systems, for example SUS304 corresponds to AISI 304 and EN 1.4301, and SS400 is broadly similar to ASTM A36. Equivalents are approximate because chemistry and property limits differ between standards.

Reference

Metal Material Grades (JIS)

Common steel, stainless, aluminum and copper grades with classification, density, tensile strength and typical uses. Click a grade symbol to copy it.