AISI 440F UNS S44020 Martensitic Stainless Steel Bars and plates
It is an improved machinability grade of 108Cr17 (11Cr17), combining the high hardness of 440C with excellent machinability. It is ideal for high-precision wear-resistant parts requiring mass production and holds an irreplaceable advantage in the field of micro and small precision components. Special attention should be paid to the influence of sulfur on performance, and reliability verification tests are recommended for critical components.
Applications of UNS S44020
Suitable for automatic lathes, automotive components (fuel injection spools, ABS system precision valves, turbocharger thrust washers), and medical devices (minimally invasive surgical drills, dental implant accessories, endoscope adjustment mechanisms).
Equivalent Grades and Commonly Used Specifications of UNS S44020
| Steel Grade | Specification | Specification Name |
| Y11Cr17 /
Y108Cr17 / S44097 |
GB/T 1220 | Stainless steel bars |
| GB/T 4356 | Stainless steel wire rods | |
| GB/T 20878 | Stainless steels–Designation and chemical composition | |
| UNS S44020 / 440F | ASTM A582/A582M | Standard Specification for Free-Machining Stainless Steel Bars |
| ASTM A959 | Standard Guide for Specifying Harmonized Standard Grade Compositions for Wrought Stainless Steels | |
| ASTM F899 | Standard Specification for Stainless Steels for Surgical Instruments | |
| SUS440F | JIS G 4303 | Stainless Steel bars |
| Produce as other form and size according to technical requirements are available. | ||
Typical Chemical Composition of UNS S44020
|
Elements |
C | Si | Mn | P | S | Ni | Cr |
Mo |
|
Contents% |
0.95~1.20 | ≤1.00 | ≤1.25 | ≤0.060 | ≥0.15 | ≤0.60 | 16.00~18.00 |
≤0.75 |
| Produce as other form and size according to technical requirements are available. | ||||||||
Typical Heat Treatment Condition and Mechanical Properties of UNS S44020
|
Delivery Condition |
Mechanical Properties of Heat-Treated Specimens | ||||||
| Rp0.2/(N/mm2) | Rm/(N/mm2) | A/% | Zb/% | Aku2d/J | HBW |
HRC |
|
|
Annealed Condition（800℃-920℃, cool slowly） |
/ | / | / | / | / | ≤269 | / |
|
Q+T（1010℃-1070℃, oil; 100℃-180℃, cool rapidly） |
/ | / | / | / | / | / | ≥58 |
| Produce as other form and size according to technical requirements are available. | |||||||
Product Forms and Size Range of UNS S44020
|
Product forms |
Size range |
|
Bars |
Diameter or side length: 5.0mm~1000mm |
| Flats |
thickness: 4.0mm~1000mm width: 300mm~2200mm |
| Produce as other form and size according to technical requirements are available. | |
