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303 Stainless Steel UNS 30300
303 Stainless Steel is the most machinable of the austenitic grades of stainless steel. With the addition of Sulfur to this grade, the sulfur enhances the alloys machinability which is ordinarily difficult to machine.
Applications: 303 Stainless is widely used in manufacture of shafts, valve bodies, valve trim and food industry applications where 304 stainless would be normally used. 303 Stainless steel is resistant to atmospheric corrosion, food products, sterilization solutions and many organic chemicals as well as a variety of inorganic chemicals.
Chemistry Analysis
| Carbon |
0.12% |
Manganese |
2.00% |
| Phosphorus |
0.20% |
Sulfur |
0.15% |
| Silicon |
1.00% |
Chromium |
17.00 - 19.00% |
| Nickel |
8.00 - 10.00% |
Iron |
67.53 - 71.53% |
Corrosion Resistance
Intergranular corrosion may be compromised if the material is heated between 800 degrees F (427 c) and 1650 F (899 C) or cooled slowly through that range.
The following table is for reference only, many factors can affect the corrosive resistance. A corrosion test for each application should be applied.
| Phosphoric acid |
Moderate |
Acetic Acid |
Moderate |
| Sodium Hydroxide |
Moderate |
Sea Water |
Restricted |
| Salt Spray |
Moderate |
Nitric Acid |
Good |
| Sulfuric Acid |
Moderate |
Humidity |
Excellent |
Typical Elevated Temperature Mechanical Properties
303 Stainless annealed condition 1900f (1038C)
| |
Short Time Tensile Tests |
Creep Tests |
| Test Temperature |
0.2% Yield Strength |
Ultimate Tensile Strength |
% Elongation in 2” (50.8mm) |
% Reduction in area |
Stress in 1% Creep in 10,000 Hours |
| F |
C |
ksi |
Mpa |
ksi |
Mpa |
ksi |
Mpa |
| 70 |
21 |
35 |
241 |
90 |
621 |
50 |
55 |
- |
- |
| 800 |
427 |
21 |
145 |
61 |
421 |
35 |
51 |
- |
- |
| 1000 |
538 |
19 |
131 |
55 |
379 |
34 |
55 |
17 |
117 |
| 1200 |
549 |
17 |
117 |
45 |
310 |
30 |
54 |
7 |
48 |
| 1400 |
760 |
14 |
97 |
30 |
207 |
31 |
45 |
2 |
14 |
| 1600 |
871 |
10 |
69 |
20 |
138 |
34 |
43 |
- |
- |
Typical Room Temperature Mechanical Properties 303 Stainless
Annealed 1900f (1038c) 1” rd bar
| 0.2% Yield Strength |
Ultimate Tensile Strength |
% Elongation in 2” (50.8mm) |
% Reduction of Area |
Brinell Hardness |
Impact Strength |
| ksi |
Mpa |
ksi |
Mpa |
Izod |
Charp V-notch |
| 35 |
241 |
90 |
621 |
50 |
55 |
160 |
80 ft-lb |
70 ft-lb |
Heat Treatment
- Annealing:
- Heat to 1850/1950 F (1010/1066c) and quench in water. Brinell hardness approximately 160.
- Hardening:
- Cannot be hardened by heat treatment. Cold working this alloy increases its strength and hardness.
- Machinability:
- 303 Stainless machines easily with a brittle chip. Grinding and polishing are possible with 303 Stainless with satisfactory results. Our forging operation can increase the results for polishing this grade.
- Specifications:
- AMS 5640 ASTM A473 ASTM A582 EN10204 DIN3.1B
- Shapes Manufactured:
- Flat Bars, Square Bars, Round Bars, Rings, Hollows, Discs, Blocks and special Shapes. Send us a drawing to see how we can save you material and machining time!
The information in this data sheet is for information only and should not be used for engineering.
