Wire, AMS 5640, ASTM A 314, ASTM A 581, ASTM A 582, QQ-S-764  


Type 303 should be considered for use in applications such as shafts, valve bodies, valves, valve trim, and fittings. This steel possesses non-galling properties that make disassembly of parts easy­and help to avoid scratching or galling in moving parts. 


Alloy 303 alloy is a free-machining stainless steel specifically designed to exhibit improved machinability. It is a non-magnetic austenitic stainless steel which is not hardenable by heat treatment. Sulfur is added to produce the free-machining characteristics. The good mechanical and corrosion-resistant properties of the lower-sulfur grade are retained to the extent possible.  

Chemistry Typical 

Carbon: 0.12 max  Phosphorus: 0.20 max  Sulfur: 0.150 min  Silicon: 1.00 max  Nickel: 8.00-10.00  Chromium: 17.00-19.00  Manganese: 2.00 max  Iron: Balance 

Physical Properties  

Density: 0.283 lbs/in3 8.00 g/cm3 Electrical Resistivity: ohm-cir-mil/ft: At 70 °F: 433.0  Specific Heat: BTU/lb-°F (J/g-°C):  32 - 212 °F (0 - 100 °C): 0.12 (0.5)  Thermal Conductivity: BTU-in/hr-ft2-°F (W/m•K)  At 212 °F (100 °C): 112 (16.20) 

Mean Coefficient of Thermal Expansion: µin/in-°F (µm/m-°C)  68 - 392 °F (20 - 200 °C): 9.3 (16.7)  Modulus of Elasticity: ksi (MPa)  28 x 103 (193 x 103) in tension  Melting Range: 2550 - 2590 °F (1400 - 1420 °C)


Sheet, Strip, Plate: Inquire with Ulbrich Stainless Steel Sales  Wire - Profile, Round, Square  Rectangular cross sections: Inquire with Ulbrich Shaped Wire Sales

Mechanical Properties at Room Temperature  Properties: Annealed Typical  

Ultimate Tensile Strength: 75 KSI min (517 MPa min)  Yield Strength: 25 KSI min (172 MPa min)  Elongation: 35% Min 

Properties: Tempered  

303 can be cold worked to various tempers. Contact Ulbrich Shaped Wire Technical Service for additional information. 

Additional Properties  

Corrosion Resistance    

Refer to NACE (National Association of Corrosion Engineers) for recommendations. 

Wire Finishes   

XC - Extra clean bright annealed or bright annealed and cold rolled Grease - Ultra-bright finish (for decorative applications)  Soap - Soap is not removed from tempered wire to act as a lubricant.  *Contact Ulbrich Wire for custom finishes.

Heat Treatment 

303 is non hardenable by heat treatment. 


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 & 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.


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