303 (UNS S30303)

303 Austenitic Stainless Steel
UNS S30303


Austenitic stainless steel 303 (UNS S30303) is specially designed to improve machinability

by adding sulfur on the basis of stainless steel with 10% chromium and 8% nickel, while maintaining the original mechanical properties and corrosion resistance and enhancing its cutting ability.

303 (UNS S30303) is a kind of non-magnetic austenitic stainless steel that can’t be hardened by heat treatment.

Chemical composition of 303 (UNS S30303) (%):  

Grade         C            Mn        Si           P             S              Cr          Mo           Ni         

304  min.      --            - -          --            --           0.15         17.0        --             8.0         
        max.    0.15       2.0        1.00       0.20         --             19.0      0.60        10.0      

Corrosion resistance of 303 (UNS S30303)
Some kinds of substance being Added can enhance the machinability while at the same time, corrosion resistance can slightly be reduced. Under dry and mild surroundings, the cutting ability doesn’t change, and in most cases, the cutting ability of performance remains the same.


The stainless steel with cutting class is not recommended to do welding process, but it can still be welded with difficulty. Alloy 303 and alloy 310 should be annealed in order to dissolve the carbide precipitation after welding, which increases the material's resistance to intergranular corrosion.


Popularlly used ways can also be used for general 303 (UNS S30303) . High processing rates under annealed state and hardness between 200-240 Brinell can be achieved. However, the improvement should be done to adjust the characteristics of a variety of stainless steel.

Annealing temperature

To achieve maximum scalability, 303 (UNS S30303) should be annealed between 1800 - 2000 ° F (982-1043 ° C), and the upper limit is better. In order to avoid harmful carbide production, material should be cooled by quenching with water and material should be avoided to be heated between the 800 - 1500 ° F (427 - 816 ° C).

Hardening temperature

Alloy 303 is a kind of austenitic stainless steel, which can’t be hardened by heat treatment.


When heated under 800 - 1500 ° F (427 - 816 ° C), the carbon compounds will be precipitated around the grain boundaries. When Re-annealled, these carbon compounds will be redissolved.


Stainless steel 303 (UNS S30303) is typically used on:

nuts & bolts
aircraft fittings
electrical switchgear components

Please contact our company service (hotline:86 0510-83,632,628) to get more information on 303 (UNS S30303) about selection, application, heat treatment and inventory and other related information,you can also contact us for more information about  austenitic stainless steel and  stainless steel.

【Hits:】 【Add:2013-02-18】 【Close

HongChao (DongGuan) Stainless Steel,INC.

#408 Tangxia Road, Lin cun

Tangxia town,Dongguan city


We appreciate your questions&visits to our company!

Contact Us

Sales Representative

Jonny: +86-189 2559 7988

Phone: +86-769-82621066

Fax:     +86-769-87728886



Enterprise Culture