🟦 Product Overview
440C Stainless Steel Bar is the highest‑carbon and highest‑hardness grade in the 440 series (440A / 440B / 440C). It is known globally for:
- Extremely high hardness (up to 58–60 HRC)
- Excellent wear resistance
- Good corrosion resistance
- High polishability
- Magnetic martensitic structure
440C is widely used in:
- High‑end knives & blades
- Bearings & races
- Valve components
- Molds & dies
- Precision mechanical parts
- Wear‑resistant tools
Compared with 410 / 420:
- Much higher carbon → much higher hardness
- Superior wear resistance
- Better edge retention
- Higher strength after heat treatment
It is the premium martensitic stainless steel for applications requiring maximum hardness and durability.
🟦 Standards
- ASTM A276
- ASTM A479
- EN 10088
- JIS G4303 SUS440C
- GB/T 1220 9Cr18Mo
🟦 Grade Included
- 440C Stainless Steel (UNS S44004 / 1.4125)
🟦 Product Specifications & Available Sizes
Shapes Available
- Round Bar
- Square Bar
- Hex Bar
- Flat Bar
Diameter Range
Length
Surface Conditions
- Hot Rolled
- Cold Drawn
- Peeled / Turned
- Polished
- Quenched & Tempered (Q+T)
🟦 Chemical Composition（440C）
| Element | Content (%) |
|---|
| C | 0.95–1.20 |
| Mn | ≤ 1.00 |
| Si | ≤ 1.00 |
| P | ≤ 0.040 |
| S | ≤ 0.030 |
| Cr | 16.0–18.0 |
| Mo | ≤ 0.75 |
📌 Very high carbon content is the key to 440C’s extreme hardness.
🟦 Mechanical Properties（Annealed Condition）
| Property | Requirement |
|---|
| Tensile Strength | 760–900 MPa |
| Yield Strength | ≥ 450 MPa |
| Elongation | ≥ 12% |
| Hardness | ≤ 225 HB |
🟦 Mechanical Properties（After Q+T Heat Treatment）
| Property | Requirement |
|---|
| Tensile Strength | 1100–1400 MPa |
| Yield Strength | 800–1000 MPa |
| Hardness | 58–60 HRC |
📌 440C is one of the hardest stainless steels available.
🟦 Physical Properties
| Property | Value |
|---|
| Density | 7.75 g/cm³ |
| Magnetic | Yes |
| Thermal Conductivity | 24 W/m·K |
| Corrosion Resistance | Good (higher than 410/420) |
🟦 Manufacturing Processes
- Hot Rolling
- Cold Drawing
- Turning / Peeling
- Grinding / Polishing
- Quenching & Tempering
- Straightening
- Ultrasonic Testing
🟦 Primary Industry Usage
- High‑end knives & cutting tools
- Bearings & races
- Valve components
- Molds & dies
- Wear‑resistant mechanical parts
- Measuring tools
- Precision instruments
🟦 Why Use 440C Stainless Steel Bar
- Maximum hardness (58–60 HRC)
- Excellent wear resistance
- Good corrosion resistance
- High polishability
- Ideal for precision and high‑load applications
🟦 Why Choose WelSteels
- Full size range of 440C stainless bars
- Hot rolled, cold drawn, polished, and Q+T options
- MTC 3.1 + third‑party inspection
- Export‑grade packaging
- Competitive pricing for global buyers
Global Stainless Steel Grade Cross‑Reference Table
| No | China | Japan | America | Korea | Germany | India | Australia | Taiwan, China |
| | GB | JIS | ASTM | UNS | KS | DIN | BIS | AS | CNS |
| Austenitic Stainless Steel |
| 1 | 12Cr17Mn6Ni5N | SUS201 | 201 | S20100 | STS201 | 1.4372 | 10Cr17Mn6Ni4N20 | 201-2 | 201 |
| 2 | 12Cr18Mn9Ni5N | SUS202 | 202 | S20200 | STS202 | 1.4373 | – | – | 202 |
| 3 | 12Cr17Ni7 | SUS301 | 301 | S20200 | STS301 | 1.4319 | 10Cr17Ni7 | 301 | 301 |
| 4 | 06Cr19Ni10 | SUS304 | 304 | S30400 | STS304 | 1.4301 | 07Cr18Ni9 | 304 | 304 |
| 5 | 022Cr19Ni10 | SUS304L | 304L | S30403 | STS304L | 1.4306 | 02Cr18Ni11 | 304L | 304L |
| 6 | 06Cr19Ni10N | SUS304N1 | 304N | S30451 | STS304N1 | 1.4315 | – | 304N1 | 304N1 |
| 7 | 06Cr19Ni9NbN | SUS304N2 | XM21 | S30452 | STS304N2 | – | – | 304N2 | 304N2 |
| 8 | 022Cr19Ni10N | SUS304LN | 304LN | S30453 | STS304LN | – | – | 304LN | 304LN |
| 9 | 10Cr18Ni12 | SUS305 | 305 | S30500 | STS305 | 1.4303 | – | 305 | 305 |
| 10 | 06Cr23Ni13 | SUS309S | 309S | S30908 | STS309S | 1.4833 | – | 309S | 309S |
| 11 | 06Cr25Ni20 | SUS310S | 310S | S31008 | STS310S | 1.4845 | – | 310S | 310S |
| 12 | 06Cr17Ni12Mo2 | SUS316 | 316 | S31600 | STS316 | 1.4401 | 04Cr17Ni12Mo2 | 316 | 316 |
| 13 | 06Cr17Ni12Mo2Ti | SUS316Ti | 316Ti | S31635 | – | 1.4571 | 04Cr17Ni12MoTi20 | 316Ti | 316Ti |
| 14 | 022Cr17Ni12Mo2 | SUS316L | 316L | S31603 | STS316L | 1.4404 | ~02Cr17Ni12Mo2 | 316L | 316L |
| 15 | 06Cr17Ni12Mo2N | SUS316N | 316N | S31651 | STS316N | – | – | 316N | 316N |
| 16 | 022Cr17Ni13Mo2N | SUS316LN | 316LN | S31653 | STS316LN | 1.4429 | – | 316LN | 316LN |
| 17 | 06Cr18Ni12Mo2Cu2 | SUS316J1 | – | – | STS316J1 | – | – | 316J1 | 316J1 |
| 18 | 022Cr18Ni14Mo2Cu2 | SUS316J1L | – | – | STS316J1L | – | – | – | 316J1L |
| 19 | 06Cr19Ni13Mo3 | SUS317 | 317 | S31700 | STS317 | – | – | 317 | 317 |
| 20 | 022Cr19Ni13Mo3 | SUS317L | 317L | S31703 | STS317L | 1.4438 | – | 317L | 317L |
| 21 | 06Cr18Ni11Ti S | SUS321 | 321 | S32100 | STS321 | 1.4541 | 04Cr18Ni10Ti20 | 321 | 321 |
| 22 | 06Cr18Ni11Nb | SUS347 | 347 | S34700 | STS347 | 1.4550 | 04Cr18Ni10Nb40 | 347 | 347 |
| Duplex Stainless Steel |
| 1 | – | SUS329J1 | 329 | S32900 | STS329J1 | 1.4477 | – | 329J1 | – |
| 2 | 022Cr23Ni5Mo3N | – | S32205 | F60 | – | 1.4462 | – | 2205 | 2205 |
| 3 | 022Cr25Ni7Mo4N | – | S32750 | F53 | – | 1.4410 | – | 2507 | 2507 |
| Ferrite stainless steel |
| 1 | 06Crl3Al | SUS405 | 405 | S40500 | STS405 | 1.4002 | 04Cr13 | 405 | 405 |
| 2 | 022Cr11Ti | SUH409 | 409 | S40900 | STS409 | 1.4512 | – | 409L | 409L |
| 3 | 022Cr12 | SUS410L | – | – | STS410L | – | – | 410L | 410L |
| 4 | 10Cr17 | SUS430 | 430 | S43000 | STS430 | 1.4016 | 05Cr17 | 430 | 430 |
| 5 | 10Cr17Mo | SUS434 | 434 | S43400 | STS434 | 1.4113 | – | 434 | 434 |
| 6 | 022Cr18NbTi | – | – | S43940 | – | 1.4509 | – | 439 | 439 |
| 7 | 019Cr19Mo2NbTi | SUS444 | 444 | S44400 | STS444 | 1.4521 | – | 444 | 444 |
| Martensitic Stainless Steel |
| 1 | 12Cr12 | SUS403 | 403 | S40300 | STS403 | – | – | 403 | 403 |
| 2 | 12Cr13 | SUS410 | 410 | S41000 | STS410 | 1.4006 | 12Cr13 | 410 | 410 |
| 3 | 20Cr13 | SUS420J1 | 410 | S42000 | STS420J1 | 1.4021 | 20Cr13 | 420 | 420J1 |
| 4 | 30Cr13 | SUS420J2 | – | – | STS420J2 | 1.4028 | 30 Cr13 | 420J2 | 420J2 |
| 5 | 68Cr17 | SUS440A | 440A | S44002 | STS440A | – | – | 440A | 440A |
