Stainless Steel 440C is a premium high-carbon martensitic stainless steel known for its exceptional hardness, outstanding wear resistance, and excellent edge retention after heat treatment. With the highest carbon content among the 440 series, SS 440C delivers superior strength and abrasion resistance, making it ideal for high-load and high-wear applications. While its corrosion resistance is slightly lower than 440A and 440B, it still performs well in mildly corrosive environments. Grade 440C is widely used in precision bearings, cutting tools, molds, valve parts, aerospace components, and high-performance mechanical assemblies where maximum durability and dimensional stability are critical.
Forged SS 440C bars for heavy-duty wear and load conditions
UNS S44004 forged stainless steel material traceability
ASTM A276 certified forged bar manufacturing
Heat treated forgings deliver maximum hardness and durability
440C STAINLESS STEEL ROUND BAR EQUIVALENT GRADES
STANDARD
UNS
WNR.
SS 440C
S44004
1.4125
SPECIFICATION OF STAINLESS STEEL 440C ROUND BAR
Stainless Steel Round Bar Specification
ASTM A276 / A479, ASME SA276 / A479
Dimension Standard
EN, DIN, JIS, ASTM, BS, ASME, AISI
Size
14 mm – 300 mm
Thickness
50 mm to 6000 mm Long
Length
1 to 6 Meters, Custom Cut Length
Form
Round, Square, Hex (A/F), Rectangle, Billet, Ingot, Forging Etc.
CHEMICAL COMPOSITION OF STAINLESS STEEL 440C ROUND BAR
Grade
C %
Mn %
Si %
P %
S %
Cr %
Ni %
440C
0.95 – 1.20
1.00 max
1.00 max
0.040 max
0.030 max
16.0 – 18.0
—
MECHANICAL PROPERTIES OF STAINLESS STEEL 440C ROUND BAR
Tempering Temperature (°C)
Tensile Strength (MPa)
Yield Strength 0.2% Proof (MPa)
Elongation (% in 50 mm)
Hardness Rockwell C (HRC)
Impact Charpy V (J)
Annealed*
758
448
14
269 HB max
—
204
2030
1900
4
59
9
260
1960
1830
4
57
9
316
1860
1740
4
56
9
371
1790
1660
4
56
9
* Annealed properties are typical for Condition A of ASTM A276.
Brinell hardness shown is the ASTM A276 specified maximum for annealed 440C.
💡 Practical Difference in Use
Use Stainless Steel 440C Round Bars when: extremely high hardness, exceptional wear resistance, superior edge retention, and long service life are required in aggressive mechanical applications. SS 440C is a high-carbon martensitic stainless steel offering the highest hardness among the 400-series stainless grades. After proper heat treatment, it achieves outstanding abrasion resistance and load-bearing capability, making it ideal for precision components exposed to continuous friction and heavy stress.
→ Example: bearing races, precision bearings, cutting tools, knives, valve seats, mechanical seals, gauge components, aerospace parts, and high-load wear components.
Heat Treated / Ground / Bright Finished Stainless Steel 440C Round Bars when: maximum dimensional accuracy, ultra-smooth surface finish, peak hardness, and superior fatigue resistance are required for critical engineering parts. Ground and polished bars deliver excellent straightness and tight tolerances, while optimized heat treatment ensures consistent hardness and exceptional wear life.
→ Example: CNC precision shafts, bearing rollers, hardened pins, tooling spindles, aerospace fittings, surgical tools, high-performance seals, and ultra-wear components.
Applications of Stainless Steel 440C Round Bars
Stainless Steel 440C round bars are widely used in aerospace, bearing manufacturing, tooling, medical devices, valve production, and precision engineering where maximum hardness, wear resistance, and dimensional stability are critical.
