Stainless Steel 420 is a high-carbon martensitic stainless steel renowned for its exceptional hardness, excellent wear resistance, and ability to achieve a superior polished finish after heat treatment. It offers moderate corrosion resistance along with outstanding cutting-edge retention. Grade 420 is widely used in surgical instruments, cutlery, blades, molds, and precision tools. Its high strength, excellent toughness, and mirror-finish capability make Stainless Steel 420 the preferred choice for medical, industrial, and consumer cutting applications.
Heat treated forgings for high hardness applications
Ideal for tooling and heavy mechanical service
420 STAINLESS STEEL ROUND BAR EQUIVALENT GRADES
STANDARD
UNS
WNR.
JIS
SS 420
S42000
1.4021
SUS 420
SPECIFICATION OF STAINLESS STEEL 420 ROUND BAR
Standard
ASTM A276 / A479, ASME SA276 / SA479
Dimension Standard
EN, DIN, JIS, ASTM, BS, ASME, AISI
Size
14 mm – 300 mm
Length
1 to 6 Meters, Custom Cut Length
Form
Round, Square, Hex (A/F), Rectangle, Billet, Ingot, Forging etc.
CHEMICAL COMPOSITION OF STAINLESS STEEL 420 ROUND BAR
Grade
C %
Mn %
Si %
P %
S %
Cr %
Ni %
420
0.15 max
1.00 max
1.00 max
0.04 max
0.03 max
12.0 – 14.0
0.50 max
MECHANICAL PROPERTIES OF STAINLESS STEEL 420 ROUND BAR
Condition
Tensile Strength (MPa)
Yield Strength 0.2% (MPa)
Elongation (%)
Hardness (Brinell HB)
Annealed
655
345
25
241 max
Tempered at 399°F (204°C)
1600
1360
12
444
Tempered at 600°F (316°C)
1580
1365
14
444
Tempered at 800°F (427°C)
1620
1420
10
461
Tempered at 1000°F (538°C)
1305
1095
15
375
Tempered at 1099°F (593°C)
1035
810
18
302
Tempered at 1202°F (650°C)
895
680
20
262
* Annealed tensile properties are typical for Condition A of ASTM A276; annealed hardness is the specified maximum.
💡 Practical Difference in Use
Use Stainless Steel 420 Round Bars when: very high hardness, excellent wear resistance, good surface finish, and moderate corrosion resistance are required. SS 420 contains higher carbon than SS 410, allowing it to achieve superior strength and edge retention after heat treatment. It is ideal for precision components where durability and polish quality are important.
→ Example: surgical instruments, cutting tools, blades, valve components, bearings, shafts, mould parts, and machine components.
Heat Treated Stainless Steel 420 Round Bars when: maximum hardness, superior abrasion resistance, and long service life under continuous mechanical stress are required. Proper hardening and tempering significantly improve load capacity and surface durability.
→ Example: knives, industrial cutters, dies, punches, turbine components, automotive transmission parts, mining tools, and heavy-duty fasteners.
Applications of Stainless Steel 420 Round Bars
Stainless Steel 420 round bars are widely used in tooling, medical, mechanical, and industrial applications where high hardness, wear resistance, polishability, and dependable performance are essential.
