S. S. 304 / 304L / 304H

Back To Alloys
UNS - S30400 / S30409 / S30403

Stainless Steel Grade 304 is the standard 18/8 (18% chrome, 8% nickel) austenitic stainless steel. It is a non-magnetic alloy in the annealed condition, however, becomes magnetic as it is cold worked. It is the most ordinarily utilized of all stainless grades. T304 can be effortlessly welded and is the preferred for many deep drawn, spun or formed parts due to its high ductility.

Stainless Steel Grade 304L has oxidation resistance to a maximum temperature of 1650°F (899°C) continuous without considerable scaling. The maximum temperature for intermittent presentation is 1500°F (816°C). Since 304L is an additional low-carbon variety of 304 it can frequently be utilized in the “as-welded” condition (without annealing), even in severe corrosive conditions, except for applications indicating stress relief. 304L has good welding qualities and can be welded by all standard strategy; however, consideration should be paid to maintain a strategic distance from weld “hot cracking”. To relieve stress during severe forming or spinning welding may be followed by annealing.

Stainless Steel Grade 304H includes a high carbon content making the steel more suitable for utilization in applications where high temperatures are available. The benefit of this grade is that it is an austenitic chromium-nickel steel alloy as well as the greater carbon content distribute to increased tensile and yield strength. The material is recommended for utilizing in ASME pressure vessels in working service above 525° C because of the grade's heat resistant properties.

Characteristics
  • Forming and welding properties
  • Corrosion / oxidation resistance thanks to the chromium content
  • Deep drawing quality
  • Excellent toughness, even down to cryonegic temperatures which are defined as very low temperatures
  • Low temperature properties responding well to hardening by cold working
  • Ease of cleaning, ease of fabrication, beauty of appearance
  • Excellent combination of strength and fabricability.

Applications
  • Air Bag Sensors
  • Clamps
  • Bellows
  • Flexible Hoses
  • Hinges
  • Cryogenic Components
  • Surgical Instruments
  • Pressure Vessels
  • Oil Well Filter Screen
  • Hypodermic Needles
  • Medical Parts
  • Tubing


Corrosion Resistance

304 & 304L have magnificent resistance to corrosive environment, for example textile, chemical and petroleum industries. They are found suitable in dairy and food industries as well as perform exceptionally well in rural and industrial atmospheric exposure.

Machining

To work harden slow speeds and heavy feeds will minimize this alloy’s tendency. Because of long stringy chips, the utilization of chip breakers is prudent. Many organizations now offer premium machinability grades, for example CarTech with their Project 70 and 7000 series.

Welding

All fusion and resistance process have been successfully utilized in welding 304. AWS E/ER308 or 312 filler metal is recommended. Many users choose 304L for cleaner and stronger welds which have a controlled low carbon content designed to reduce carbide precipitation at the weld boundaries.

Hot Working

Forging, heading and other hot working should be followed uniform heating to range between 2100-2300 F (1149-1260 C). Fast cooling is necessary to attain maximum corrosion resistance in finished parts.

Cold Working

Promptly fabricated by most cold working technique, 304 may require intermediate annealing to avoid cracking or tearing from radical deformation. Full annealing ought to be followed any operation to decrease internal stress and optimize corrosion resistance.

Annealing

1850-2050 F (1010-1121 C) followed by fast cooling.

Hardening

This alloy doesn’t reply to heat treatment. Cold work will motivate in an increase both hardness and strength.

Chemical Composition %

GradeCNSiPSCrMnNiFe
3040.08 max0.10 max0.75 max0.045 max0.030 max18.0 - 20.02.0 max8.0 - 10.5Remainder
304L0.03 max0.10 max0.75 max0.045 max0.030 max18.0 - 20.02.0 max8.0 - 12.0Remainder
304H0.04 - 0.100.10 max0.75 max0.045 max0.030 max18.0 - 20.02.0 max8.0 - 10.5Remainder

Mechanical Properties

GradeTensile Strength (ksi)0.2% Yield Strength (ksi)Elongation% in 2 inches
304753040
304L702540
304H753040

Physical Properties

UnitsTemperature in °C
Density8.03 g/cm³Room
Specific Heat0.12 Kcal/kg.C22°
Melting Range1399 - 1454 °C-
Modulus of Elasticity 193 KN/mm²22°
Electrical Resistivity72 µΩ.cmRoom
Coefficient of Expansion16.9 µm/m °C20 - 100°
Thermal Conductivity16.2 W/m -°K20°

ASTM Specifications

Pipe / Tube (SMLS)Sheet / PlateBarForgingFitting
A 213A 240, A 666A 276 A 182A403

Availability

Manufacturing
Refractory Anchors
Fasteners
Custom Machining
Custom Fabrication
Piping / Spools
Stamped Parts
B/W Fittings
S/W Fittings
Flanges
Compression Fittings
Raw Materials
Pipes
Tubes
Bars
Sheets
Plates
Get To Quote
Please Contact Us