What Is AISI 440A Hot Rolled Stainless Steel Round Bar?
AISI 440A hot-rolled stainless steel round bar is a high-carbon martensitic stainless steel with good strength, excellent hardness and wear resistance, and moderate corrosion resistance, presented in a solid cylindrical shape. It is a heat-treatable alloy, meaning its properties, particularly hardness and corrosion resistance, can be optimized after quenching and tempering.
SS 440A round bars are widely used in industrial shafts, cutting tools, valve components, pump parts, and mechanical wear parts requiring strength, durability, and dimensional stability.
What are the differences between AISI 440A stainless steel and 304 stainless steel?
Compared to austenitic stainless steels such as 304 or 316, AISI 440A stainless steel has significantly higher hardness and wear resistance, high hardness after quenching (up to 50-54 HRC), better corrosion resistance than 440B and 440C, and good machinability in the annealed state. It is suitable for load-bearing and wear-resistant applications.
AISI 440A Hot Rolled Stainless Steel Round Bar Specifications
| Item | Description |
|---|---|
| Material Grade | AISI 440A |
| Steel Type | Martensitic Stainless Steel |
| Standard | ASTM A276 / ASTM A479 |
| Bar Shape | Round Bar |
| Diameter Range | 10 mm – 300 mm |
| Length | 3000 – 6000 mm (cut-to-length available) |
| Manufacturing Process | Hot Rolled |
| Condition | Annealed / Heat Treatable |
| Surface Finish | Black / Peeled / Turned |
| Certification | MTC, Chemical Analysis, SGS/BV (on request) |
Chemical Composition of AISI 440A Stainless Steel (wt.%)
| Element | Content |
|---|---|
| Carbon (C) | 0.60 – 0.75 |
| Chromium (Cr) | 16.0 – 18.0 |
| Manganese (Mn) | ≤ 1.00 |
| Silicon (Si) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.040 |
| Sulfur (S) | ≤ 0.030 |
| Iron (Fe) | Balance |
Mechanical Properties of AISI 440A (Typical, Heat Treated)
| Property | Value |
|---|---|
| Tensile Strength | 700 – 850 MPa |
| Yield Strength | 450 – 550 MPa |
| Elongation | 15 – 20% |
| Hardness | 50 – 54 HRC |
| Impact Toughness | Moderate |
What is AISI 440A hot rolled stainless steel round bar used for?
It is used for mechanical parts, shafts, cutting tools, and wear-resistant components requiring high hardness and moderate corrosion resistance.
Can AISI 440A round bars be heat treated?
Yes. AISI 440A is fully hardenable, achieving 50–54 HRC after proper quenching and tempering.
Is 440A stainless steel corrosion resistant?
440A offers good corrosion resistance for a martensitic grade, performing better than 440B and 440C in mild corrosive environments.
440A steel bar supplier-GNEE
GNEE is a reliable supplier of 440 stainless steel round bars, typically available in diameters ranging from Ø6 mm to Ø450 mm, and offered in solution annealed or solution annealed and aged conditions.
All 440A stainless steel round bars are manufactured according to ASTM A276 and ASTM A479 standards and can be supplied with EN 10204 3.1 certificates.
GNEE offers various product forms, such as hot-rolled bars, forged bars, peeled bars, polished bars, and cut-to-length bars, to meet different processing and performance requirements.
For transportation and packaging, the round bars are treated with anti-rust oil, plastic wrapped, and packaged in seaworthy wooden crates or steel-banded bundles.
