440A Stainless Steel Wire UNS S44002
Alloy 440A is a high carbon straight chromium martensitic stainless steel.
Shaped, Flat, Square, Round, Fine Wire, Plated and Bare Wire ASTM A 276
440A Alloy Description
Alloy 440A is a high carbon straight chromium martensitic stainless steel. It combines the superior wear resistance of high carbon alloys with the excellent corrosion resistance of chromium stainless steels. It is magnetic in both the annealed and hardened conditions. Maximum corrosion resistance is attained only in the fully hardened condition.
Medical and dental instruments
Cutlery and scissors
Manganese: 1.00 max
Phosphorus: 0.04 max
Sulfur: 0.03 max
Silicon: 1.00 max
Molybdenum: 0.75 max
Density, 0.280 lbs/in³, 7.74 g/cm³
Electrical Resistivity, microhm-in (microhm-cm):
68°F (20°C): 23.7 (60.0)
Specific Heat, BTU/lb/°F (kJ/kg•K):
32-212°F (0-100°C): 0.11 (0.46)
Thermal Conductivity, BTU/hr/ft²/ft/°F (W/m•K):
At 212°F (100°C): 14.0 (24.2)
Mean Coefficient of Thermal Expansion, in/in/°F,(μm/m•K):
32-212°F (0-100°C): 5.7 x 10 (10.2)
32-1200°F (0-649°C): 6.8 x 10 (12.1)
Modulus of Elasticity, KSI (MPa)
29.0 x 10³ (200 x10³) in tension
Magnetic Permeability: Magnetic
Mechanical Properties at Room Temperature
Properties: Annealed Typical
Ultimate Tensile Strength: 100 KSI max (690 MPa max)
Yield Strength (0.2% offset): 65 KSI max (448) MPa max)
Elongation: 15% min
HV 256 max: gauges < 0.010 inches
Rb 100 max: gauges > 0.010 inches
Alloy 440A can be cold rolled to achieve the temper properties required by specific
customers and/or manufacturing requirements. Contact Ulbrich Wire for details.
Alloy 440A provides full corrosion resistance only in the hardened or hardened and stress-relieved conditions. Type 440A has good corrosion resistance to atmosphere, fresh water, foods, alkalies and mild acids.
Standard Wire Finishes
Extra Clean: Extra clean is also referred to as “bright annealed” or “bright annealed and cold rolled”
Grease (round wire only): Drawn in a heavy grease produces an “Ultra bright” finish for
Soap (round wire only): Soap is used as a lubricant in the drawing process and is not
removed. It acts as a lubricant during customer part forming operation. A soap finish is
available in tempered products.
Plated: Many plating options are available.
∗Special finishes are available: Contact Ulbrich Wire Sales with special finish and plating requests.
Cut to lengths
Alloy 440A has limited formability in the annealed condition
Hardening: Alloy 440A can be hardened cold working and by heat treatment. Contact
Ulbrich Technical Service for additional information
For best results refer to: SSINA’s “Welding of STainless Steels and Other Joining Methods”
Limitation of Liability and Disclaimer of Warranty: In no event will Ulbrich Stainless Steels and Special Metals, Inc., be liable for any damages arising from the use of the information included in this document or that it is suitable for the ‘applications’ noted. We believe the information and data provided to be accurate to the best of our knowledge but, all data is considered typical values only. It is intended for reference and general information and not recommended for specification, design or engineering purposes. Ulbrich assumes no implied or express warranty in regard to the creation or accuracy of the data provided in this document