chekc Difference Between A4 and A2 Stainless Steel
Both of these are made of austenitic stainless steel. The fundamental distinction between these materials that affects their mechanical qualities and other characteristics is their composition. The composition of the a4 substance includes 10.5 percent nickel, 2 percent molybdenum, and 16 percent chromium. The composition of the a2 substance contains 10.5 percent chromium. Corrosion resistance in the a4 material is substantially higher than in the a2 material. The enhanced corrosion resistance of the a4 grade material is primarily why it is employed in marine grade applications. The addition of molybdenum to the composition gives the a4 material its strong corrosion resistance.
Cold-worked austenitic stainless steel is used to create the materials, which fall into five categories, A1 through A5. A2-70 and A4-80 are two examples of subgrades for each A grade. The specified numbers typically represent the minimum tensile strength in MPa. The minimum tensile strength for the A2-70 is 700 MPa, and the minimum tensile strength for the A4-80 is 800 MPa. Both materials are capable of withstanding temperatures of up to 870 degrees Celsius.
TTemperatures over this range can result in the precipitation of chromium carbide and lessen the materials' ability to resist corrosion. However, by heating and cooling the material using the annealing processes, the materials' hardness might be increased. It can be utilised in applications including food manufacturing, transportation, and other industries since annealing allows it to keep strength, become harder, and resist corrosion.
The a2 grade is a more versatile option that can be utilised in household and broad corrosive service applications. The a4 grade is appropriate for usage in highly corrosive environments, including marine, seawater, food-grade, and medical implants.
With the exception of printed markings on the products, visual identification is challenging. Various tests can be used to determine the steel grades A2 and A4. Applying saline solutions and letting the items sit for 24 hours would be a straightforward test to check for any rust or stain formation. The A4 material would not develop much discoloration as quickly as the A2 material. In addition to that, any metallurgic laboratory can do other laboratory testing.
These materials have comparable strengths. The A4 grade has a minimum yield strength of 600MPa and a minimum tensile strength of 800MPa. The minimum yield strength and tensile strength for the A2 grade are both 450 MPa. These materials could not be heat treated to increase their strength.
| GRADE | C | MN | P | S | SI | CR | NI | CU | |
|---|---|---|---|---|---|---|---|---|---|
| A2-70 | Min | - | - | - | - | - | 15.0 | ||
| Max | 0.1 | 2.0 | 0.05 | 0.03 | 1.0 | 20.0 | 19.0 | 4.0 | |
| 304 | Min | - | - | - | - | - | 18.0 | 8.0 | |
| Max | 0.08 | 2.0 | 0.045 | 0.03 | 0.75 | 20.0 | 10.5 | ||
| 304L | Min | - | - | - | - | - | 18.0 | 8.0 | |
| Max | 0.03 | 2.0 | 0.045 | 0.03 | 0.75 | 20.0 | 12.0 | ||
| 304H | Min | 0.04 | - | - | - | - | 18.0 | 8.0 | |
| Max | 0.10 | 2.0 | 0.045 | 0.03 | 0.75 | 20.0 | 10.5 |
Stainless Steel A4 Bolts
Stainless steel grade a2-80 Screws
stainless steel A2-80 Studs
IS 1367 grade a2-70 Nuts and Bolts
Grade A4 Stainless Steel Washer
| FASTENERS GRADE | SI | C | P | MN | S | MO | CR | NI | N | CU | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Max | ISO | 1.00 | 0.08 | 0.045 | 2.00 | 0.03 | 3.0 | 18.5 | 14.0 | - | 1.0 |
| Min | A4-70 | - | - | - | - | - | 2.0 | 16.0 | 10.5 | - | - |
| Max | ISO² | 1.00 | 0.03 | 0.045 | 2.00 | 0.03 | 3.0 | 18.5 | 14.0 | 0.22 | 1.0 |
| Min | A4-70 | - | - | - | - | - | 2.0 | 16.0 | 11.5 | 0.12 | - |
| Max | 0.75 | 0.08 | 0.045 | 2.0 | 0.03 | 3.00 | 18.0 | 14.0 | 0.10 | ||
| Min | 316 | - | - | 0 | - | - | 2.00 | 16.0 | 10.0 | - | |
| Max | 0.75 | 0.03 | 0.045 | 2.0 | 0.03 | 3.00 | 18.0 | 14.0 | 0.10 | ||
| Min | 316L | - | - | - | - | - | 2.00 | 16.0 | 10.0 | - | |
| Max | 0.75 | 0.10 | 0.045 | 0.10 | 0.03 | 3.00 | 18.0 | 14.0 | - | ||
| Min | 316H | 0 | 0.04 | - | 0.04 | - | 2.00 | 16.0 | 10.0 | - |
