Stainless Steel 440A seamless tubes and hollows (UNS S44002) are suited to applications that need a hardenable stainless steel with good corrosion resistance. With 0.60% to 0.75% carbon and 16% to 18% chromium, 440A has the lowest carbon content in the 440 series. That gives it a better balance of toughness and corrosion resistance than 440B and 440C, while still allowing the material to be hardened when required. Amardeep Steel supplies SS 440A seamless tubes and hollows with EN 10204 3.1 mill test certificates, heat treatment records and complete heat traceability. Compare our SS 440B seamless pipes and tubes and SS 440C seamless pipes and tubes, or see our SS 440 tubes.
What Are Stainless Steel 440A Seamless Pipes & Tubes?
Grade 440A hardens by heat treatment to a high, wear resistant hardness while keeping reasonable corrosion resistance. It is chosen where a part must hold an edge or resist wear but also see moisture, and where 440C would be too brittle.
How 440A Seamless Tube Is Produced
High carbon 440 grades are made mainly as bar, wire and billet, and no ASTM tube specification lists them. Seamless 440A tube is therefore produced to drawing, usually by piercing or boring hollow bar, and supplied annealed for machining. The final hardness comes from the buyer's own hardening and tempering after machining, or from heat treatment we arrange to the drawing.
SS 440A Seamless Tube Specifications
Parameter | Details |
|---|---|
Grade | Stainless Steel 440A (AISI 440A) |
UNS | S44002 |
Chemistry Basis | ASTM A276 / A580 limits for the grade; tube made to drawing or purchase specification |
Type | Seamless, hot finished or cold drawn, and machined hollows |
Size Range | To drawing or purchase specification |
Length | Random, fixed and cut lengths |
Supply Condition | Annealed for machining; hardened and tempered on request |
Test Certificate | EN 10204 3.1, with 3.2 available on request |
SS 440A Chemical Composition
Element | Content (%) |
|---|---|
Carbon (C) | 0.60 to 0.75 |
Chromium (Cr) | 16.00 to 18.00 |
Molybdenum (Mo) | 0.75 max |
Manganese (Mn) | 1.00 max |
Silicon (Si) | 1.00 max |
Phosphorus (P) | 0.040 max |
Sulfur (S) | 0.030 max |
SS 440A Mechanical Properties
Property | Value |
|---|---|
Typical hardness, annealed | 95 HRB |
Typical hardness, hardened and tempered at 315 degrees Celsius | 51 HRC |
Commonly specified hardness after heat treatment | 54 HRC min |
These are typical values from published data, not specification minimums. The hardness you receive depends on section size and on the hardening and tempering cycle, which is agreed with your order.
SS 440A Equivalent Grades
Standard | Designation |
|---|---|
UNS | S44002 |
AISI | 440A |
EN / Werkstoff No. | 1.4109 (X70CrMo15), closest |
JIS | SUS440A |
GB | 7Cr17 |
Equivalent grades are close matches, not direct substitutes. Check the drawing before switching standards.
440A vs 440B vs 440C
Property | 440A | 440B | 440C |
|---|---|---|---|
Carbon | 0.60 to 0.75% | 0.75 to 0.95% | 0.95 to 1.20% |
Chromium | 16 to 18% | 16 to 18% | 16 to 18% |
Typical hardness, tempered at 315 degrees Celsius | 51 HRC | 55 HRC | 57 HRC |
Corrosion resistance | Best of the three | Middle | Lowest of the three |
Toughness | Highest | Middle | Lowest |
Carbon rises from 440A to 440C, which raises hardness and wear resistance but lowers corrosion resistance and toughness. See our SS 440 tubes for the full family and our SS 420C bars for a lower carbon martensitic option.
Applications of SS 440A Seamless Pipes and Tubes
- Cutlery and blade parts
- Valve seats and wear sleeves
- Surgical and dental instrument parts
- Pump parts in mildly corrosive service
Testing and Documentation
Every order of SS 440A seamless tube goes through the checks below at our testing facility or approved third party labs.
- Chemical analysis and PMI
- Hardness test on each heat treatment lot
- Ultrasonic or eddy current testing on request
- Visual and dimensional inspection
Mill test certificates are issued to EN 10204 3.1, with 3.2 available on request. You can view our approvals on the certificates page.
Packing and Marking
Each length is marked with grade, size, heat number and heat treatment condition. Bores are oiled and capped. Tubes are packed in bundles or wooden boxes for export. Read more about our packing and despatch process.
Request a Quote for Stainless Steel 440A Seamless Pipes & Tubes
Send us the OD, ID or wall thickness, heat treatment condition, length and quantity, and our team will reply with price and delivery. Use the enquiry form or reach us through the contact page.
Frequently Asked Questions
What is Stainless Steel 440A?
Stainless Steel 440A (UNS S44002) is a martensitic stainless steel with 0.60 to 0.75% carbon and 16 to 18% chromium that can be hardened by heat treatment.
What is the difference between 440A and 440C?
440A has less carbon (0.60 to 0.75% against 0.95 to 1.20%), so it reaches lower hardness but has better corrosion resistance and toughness.
What is the EN equivalent of 440A?
The closest EN grade is 1.4109 (X70CrMo15). The JIS equivalent is SUS440A.
Is there an ASTM tube specification for 440A?
No. 440A is covered as bar and wire. Seamless 440A tube and hollows are produced to drawing.
