AASHTO M270 Structural Steel Plate

Leeco® Steel stocks and supplies AASHTO M270 structural steel plate.


  • Certified to meet the American Association of State Highway and Transportation Officials (AASHTO) specifications for use in vehicle bridges.
  • Available in two grades: 50 and 50W.
  • Guaranteed to meet AASHTO M270 specifications, but may also be dual certified with similar ASTM grades.
  • Charpy test requirements for specific zones and climates may be requested.


Available Sizes

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

M270 50 & 50W 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 %
50 50 65 18
50W 50 70 18

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 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%



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%