Type 304 (S30400), Type 304L (S30403)

Description

Type 304/304L is the modern version of “18-8” stainless steel containing approximately 18% chromium and 8% nickel and is the most commonly specified stainless steel used throughout the world. Type 304/304L is a versatile, general purpose stainless steel with good resistance to atmospheric corrosion, and to many chemicals and food and beverages. These grades can be specified in the annealed condition where they have very good formability. Higher nickel versions can be specified to enhance multi-stage deep drawing characteristics. Higher strength, cold-worked conditions can also be specified for Type 304/304L for spring type applications. Type 304/304L is non-magnetic in the annealed condition but may become slightly magnetic as a result of cold working.

Type 304L can be dual certified as 304 when the composition meets the lower carbon limit of 304L and the slightly higher strength levels of 304. Type 304L should be specified for welded applications as the low carbon version eliminates chromium carbide precipitation and enhances the corrosion resistance in the as-welded condition.

Chemical Composition
Chemical Composition (wt%) limits as specified in ASTM A240 and ASME SA240*
Element 304 304L
Carbon 0.07 0.03 max
Chromium 17.5-19.5 17.5-19.5
Nickel 8.0-10.5 8.0-12.0
Manganese 2.00 2.00
Silicon 0.75 0.75
Nitrogen 0.10 0.10
Phosphorus 0.045 0.045
Sulfur 0.030 0.030
* Maximum, unless range is indicated
Mechanical Properties
Mechanical property requirements for annealed product as specified in ASTM A240 and ASME SA240
Property 304 304L
Yield Strength, min. (ksi) 30 25
Tensile Strength, min. (ksi) 75 70
Elongation, min. (%) 40 40
Hardness, max. (Rb) 92 92
Physical Properties
Physical properties for Type 304/304L stainless steel
Property 304/304LData
Density, lb/in3 0.285
Modulus of Elasticity, psi 28 x 106
Coefficient of Thermal Expansion, 68-212˚F, /˚F 9.2 x 10-6
Thermal Conductivity, Btu/ft hr ˚F 9.4
Specific Heat, Btu/lb ˚F 0.12
Electrical Resistivity, Microohm-in 28.3
Standards
Typical standards for Type 304/304L stainless steel
304 304L
ASTM A240 ASTM A240
ASTM A666 ASTM A666
ASME SA240 ASME SA240
AMS 5513 AMS 5511

Data are typical, are provided for informational purposes, and should not be construed as maximum or minimum values for specification or for final design, or for a particular use or application. The data may be revised anytime without notice. We make no representation or warranty as to its accuracy and assume no duty to update. Actual data on any particular product or material may vary from those shown herein.  © 2014 RMP Inc. All rights reserved.