Stainless Steel 420 (AMS 5620/AMS 5621)

Technical Data Sheet

Alloy 420 is a martensitic stainless steel of the 12% Chromium type. Due to it's Chromium content 420 will achieve high hardness. Alloy 420 is used in many different applications including surgical and dental instruments, scissors, needle valves, gears, ball bearings, magnets etc. Alloy 420 should not be used for springs or heavily stressed parts that require to be operated at sub-zero temperatures. 

Chemical Composition Limits
Weight% C P Si Fe Mn S Cr
Alloy 420 0.15 min 0.040 max 1.00 max Bal 1.00 max 0.030 max 12-14

Typical Mechanical Properties


Material Tensile Strength (Mpa) Proof Stress 0.2% (MPa) % Elongation in 2" % Reduction of Area Hardness Brinell
Alloy 420 Ann
Room Temp 1" Round Bar
655 345 25 55 196

Alloy 420 is available in Bar (Hexagon, Round, Square, Flat), Billet, Wire, Strip. For all stock availability contact Sales.

AMS 5506 Sheet / strip / plate
AMS 5620 Bars / forging (free mach)
AMS 5621 Bars / wire / forgings
ASTM A276 / ASME SA276
ASTM A314 / ASME SA314
ASTM A484 / ASME SA484
ASTM A580 / ASME SA580
BS 3S62
BS 970; 420S37 / 420S29 / 420S45
EN56B / EN56C / EN56D
WS 1.3541
WS 1.4024
WS 1.4028
UNS S42000

For more information about Alloy 420 for use in medical applications, visit our medical division at

Customer Reviews - What Customers Say About Us!

"Just wanted to say thanks for your efforts and updates"
"I always try you as you often keep stock that can't be found elsewhere"
"Prompt answer & knowledge of available material, timescale & price within a good time"
"Packaging is superb"
"Thank you for your quick response"

Every effort is made to ensure that technical specifications are accurate. However, technical specifications included herein should be used as a guideline only. All specifications are subject to change without notice.