Stainless
Stainless 304
Annealing Procedure
1850-2050 F (1010-1121 C) followed by rapid cooling.
Applications
The list is endless. Almost every conceivable industry uses some of this material in some way. Everything from stovetops to ball point pen barrels to flatware to fasteners has been fabricated from this alloy.
Cold Workability
Readily fabricated by most cold working methods, 304 may require intermediate annealing to avoid cracking or tearing from radical deformation. Full annealing should follow any operation to reduce internal stress and optimize corrosion resistance.
Hardening Procedure
This alloy does not respond to heat treatment. Cold work will cause an increase in both hardness and strength.
Hot Workability
Forging, heading and other hot working should follow uniform heating to 2100-2300 F (1149-1260 C). Rapid cooling is necessary to attain maximum corrosion resistance in finished parts.
Machinability
Slow speeds and heavy feeds will minimize this alloys tendency to work harden. Due to long stringy chips, the use of chip breakers is advisable. Many companies now offer premium machinability grades, such as CarTech with their Project 70 and 7000 series.
Principle Design Features
One of the most widely used and oldest of the stainless steels. This was originally called 18-8 which stood for its chromium and nickel content. It possesses an excellent combination of strength, corrosion resistance and fabricability. It is available in the widest variety of forms and sizes of any stainless steel.
Weldability
All fusion and resistance processes have been successfully employed in welding 304. AWS E/ER308 or 312 filler metal is recommended. For cleaner, stronger welds, may users choose 304L which has a controlled low carbon content designed to reduce carbide precipitation at the weld boundaries.
Known Forms
Angle
Bolt
Channel
Coil
Disc
Expanded Sheet
Fitting
Flange
Flat Bar
Foil
Grating
Hexagon Bar
Hollow Bar
Nut
Perforated Sheet
Pipe
Plate
Powder
Precision Ground Bar
Rectangle Tube
Ring
Rod
Round Bar
Round Tube
Screw
Sheet
Specialty Form
Square Bar
Square Tube
Standard Beam
Strip
Tee
Threaded Rod
Valve
Washer
Wire Flat
Wire Round
Wire Square
Additional Data
Specifications
Z7CN 18-09,304,5501,5513,5560,5563,5564,5565,5566,5567,5639,5697,A167,A182,A193 (304, B8, B8A),A194,A213,A240,A249,A269,A270,A271,A276,A312,A313,A314,A320,A336,A358,A368,A376,A409,A430,A473,A478,A479,A492,A493,A511,A554,A580,A632,A666,A688,A793,A813,A814,A851,1.4301,A-23196,S-23195,S-23196,S-27419,S-5059,T-5695,T-6845,T-8504,T-8506,S763,S766,S30400Chemical Elements
| Carbon | 0.08 max |
| Chromium | 18 - 20 |
| Iron | Balance |
| Manganese | 2 max |
| Nickel | 8 - 10.5 |
| Phosphorus | 0.045 max |
| Silicon | 1 max |
| Sulphur | 0.03 max |
Physical Properties
Density: 0.285lb/in³
Electrical Resistivity: 432µΩ·cm
Melting Point: 2650°F
Specific Gravity: 7.9
Specific Heat: 0.12BTU/lb·°F
Mechanical Properties
Modulus of Elasticity – Tension: 28MSI
Thermal Conductivity
| Condition | Temperature | Conductivity |
|---|---|---|
| Annealed | 212 °F | 11.3 BTU/hr·ft·°F |
| Annealed | 932 °F | 14.9 BTU/hr·ft·°F |
Thermal Expansion
| Condition | Min | Max | Expansion Coefficient |
|---|---|---|---|
| Annealed | 32 °F | 600 °F | 10.2 μin/in·°F |
| Annealed | 32 °F | 1200 °F | 10.4 μin/in·°F |
Mechanical Test Data
| Form | Strip |
| Condition | Extra Full Hard |
| Temperature | 70°F |
| Rockwell Hardness | C45 |
| Tensile Strength | 200 KSI |
| Form | Strip |
| Condition | Full Hard |
| Temperature | 70°F |
| Elongation | 8% |
| Rockwell Hardness | C41 |
| Tensile Strength | 185 KSI |
| Yield Strength | 140 KSI |
| Form | Strip |
| Condition | Half Hard |
| Temperature | 70°F |
| Elongation | 17% |
| Rockwell Hardness | C32 |
| Tensile Strength | 150 KSI |
| Yield Strength | 110 KSI |
| Form | Strip |
| Condition | Quarter Hard |
| Temperature | 70°F |
| Elongation | 25% |
| Rockwell Hardness | C25 |
| Tensile Strength | 125 KSI |
| Yield Strength | 75 KSI |
| Form | Strip |
| Condition | Three Quarter Hard |
| Temperature | 70°F |
| Elongation | 11% |
| Rockwell Hardness | C37 |
| Tensile Strength | 175 KSI |
| Yield Strength | 135 KSI |