ASTM A709 Structural Steel Plate for Bridges

Leeco® Steel stocks ample inventories of ASTM A709 steel plate in standard and high-performance grades.

Overview:

  • Common steel plate grade used primarily for the manufacture of bridges.
  • Heavy thicknesses (3-inches or thicker) available at most Leeco Steel distribution centers.
  • Available in standard grades: 36, 50 and 50W.
  • Available in high-performance grades: HPS 50W and HPS 70W.
  • Dual ASTM and AASHTO spec certifications are available.
  • Customers can specify A709 grades to meet Charpy test requirement for specific zones and climate.

 

Available Sizes

Leeco Steel stocks the following standard sizes, but other sizes may be available for special orders.

GRADE THICKNESS WIDTH LENGTH
36 3/16" – 4" 48" – 120" Up to 480"
50 3/16" – 4" 48" – 120" Up to 480"
50W 3/16" – 4" 48" – 120" Up to 480"
HPS 50W 3/16" – 4" 48" – 120" Up to 480"
HPS 70W 3/16" – 4" 48" – 120" Up to 480"

Minimum order weight in the USA is 20 tons. For orders weighing less than 20 tons, additional freight surcharges may be applied. Minimum order weight for orders outside of North America is 500 MT.

Material Properties

The following material properties are ASTM specifications and will be confirmed on the Mill Test Report.

Grade Yield Point (ksi) Tensile Strength (ksi) Min. 8” Elongation %
36 36 58-80 20
50 50 65 18
50W 50 70 18
HPS 50W 50 70 18
HPS 70W 70 85-110 19 at 2” elongation %

Chemical Composition

The following composition properties are ASTM specifications for the ASTM A709 grades. Note that the composition of chemicals ranges depending on the thickness of the material.

Grade 36  
Carbon max 0.25-0.25%
Manganese* ...
Phosphorus max 0.030-0.040%
Sulfur max 0.030-0.050%
Silicon* 0.40% max
Copper min 0.20%

 * Manganese content of 0.85 to 1.35 % and silicon content of 0.15 to 0.40 % is required for grade 36 shapes with flange thickness over 3 in.

Grade 50 (max 4" thick)  
Carbon max 0.23%
Manganese max 1.35%
Phosphorus max 0.030%
Sulfur max 0.030%
Silicon 0.15-0.40%
Columbium 0.005-0.15%
Vanadium

0.01-0.15%

 

Grade 50W Type A Type B
Carbon 0.19% max 0.20% max
Manganese 0.80-1.25% 0.75-1.35%
Phosphorus 0.030% max 0.030% max
Sulfur 0.030% max 0.030% max
Silicon 0.30-0.65% 0.015-0.50%
Nickel 0.40% max 0.50% max
Chromium 0.40-0.65% 0.40-0.70%
Copper 0.25-0.40% 0.20-0.40%
Vanadium 0.02-0.10% 0.01-0.10%

 

Grade HPS 50W & HPS 70W  
Carbon 0.11% max
Manganese 1.10-1.50%
Phosphorus 0.020% max
Sulfur 0.006% max
Silicon 0.30-0.50%
Copper 0.25-0.40%
Nickel 0.25-0.40%
Chromium 0.45-0.70%
Molybdenum 0.02-0.08%
Vanadium 0.04-0.08%
Columbium ...
Aluminum 0.010-0.040%
Nitrogen 0.015% max