While the chemistry of Stainless Steel 304l round bar might not differ very much from grade 304, the alloy certainly proves to be immensely useful. This low carbon ASME SA479 type 304l round bar has been modified to improve its weldable properties.
Since the alloy resists sensitization from grain boundary precipitates, the ASME SA276 grade 304l rod can be used in an as welded condition. However, the alteration of its carbon content would mean that there is a compromise to be expected. In the case of ASTM A479 type 304l bar, the tensile and yield strength is a property that takes a hit. So while the corrosion resistance and weldability properties are good, the a276 type 304l rod does not make a structurally sound component.
Therefore the application of the ASTM a276 grade 304l round bar must be kept limited to only those applications which require these bars to be joined by welding and do not require superior tensile strength properties. But most manufacturers add nitrogen to the alloy of 304l Stainless Steel rod, which could then bring the tensile strength properties to nearly that of its predecessor. Just like nickel and molybdenum are added to austenitic steels to stabilize their crystalline microstructure , nickel also has been added to the alloy of ss 304l flat bar.
How to know that your SS 304L Bar material is genuine or not?
First check that you SS 304 round bar or Rod comply standard of ASTM A276 or A479. Second ask test report from you supplier to verify Yield Strength, Tensile strength and Hardness. mill test certificate of AISI 316 stainless steel round bar is EN10204 3.1, 3.2. If you are buying from India it should be NABL approved material.
Spec Chart of Stainless Steel 304l round bar
ASTM A276 /ASME SA276, ASTM A479/ASME SA479
Dimensions of rod
EN, AISI, JIS, BS, DIN, ASTM, ASME
Size of Round Bars
range of Outside Diameter : 4mm to 500mm
Sizes and Schedules of Flat Bars
Size: 1/2” to 10” , thickness range: 2mm to 150mm,
Sizes Available in Hex Bars
18mm – 57mm (11/16" to 2-3/4″)
Bright Bars Size Chart In Mm
range of Outside Diameter : 4mm to 100mm
Square Bars Size Range
18mm – 47mm (11/16" to 1-3/4″)
Length of round bar
1 to 6 Meters Long or Above than it
Rough, BA Finish, Polished, NO.4 Finish, Black, Matt Finish, Bright, Turned
Chemical Composition Standard of UNS S30403 round bar
18 – 20
8 – 13
Mechanical Analysis of astm a479 type 304l bar
Yield Strength (0.2%Offset)
1400 °C (2550 °F)
Psi – 75000 , MPa – 515
Psi – 30000 , MPa – 205
Equivalent Standard of DIN 1.4306 round bars
X2CrNi18-9 / X2CrNi19-11
What is the difference between ASTM a276 type 304L Round Bar and a479 grade 304L Rod?
The 304L material is a low carbon version of the 304 austenitic stainless steel. There are different standards and specifications for different products in this grade of material. The hot finished or cold finished steel bars belong to a specification called the a276. The a479 is a specification for bars and rods for boilers and pressure vessels. The major difference is that the 2276 round bars are suitable for structural applications where the strength is the primary concern where the a479 rods can be used in applications that have higher operating temperatures.