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8640 Hot Rolled SBQ Bar

Hot rolled 8640 steel is a medium-carbon, low alloy grade that contains nickel, chromium, and molybdenum. The carbon and alloy content supports induction case hardening, improving surface hardness and wear. Eaton Steel Bar Company stocks many diameters of 8640 hot rolled steel bars to meet the market demands. We supply AISI 8640 steel bars to various industries including oil & gas, automotive and military.

1018 hot-rolled-steel-bar


Typical applications for this grade of steel include forged tools, gears, axles, crankshafts and more.

8640 Hot Rolled Steel Bar Requirements

Eaton Steel Bar Company can meet the following specifications for this grade:

  • ASTM A29
  • ASTM A322

Shapes and Sizes

Eaton Steel Bar Company supplies 8640 steel bar in a variety of sizes ranging from 3/4”- 3”. The shapes available for this grade include:

  • Rounds
  • Rounded Cornered Square


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Standard "8640 Grade" Chemical Composition

Carbon 0.38-0.43
Manganese 0.75-1.00
Phosphorus (max) 0.035
Sulfur (max) 0.040
Silicon 0.15-0.35
Nickel 0.40-0.70
Chromium 0.40-0.60
Molybdenum 0.15-0.25


Estimated Mechanical Property Ranges for "Grade 8640"

Tensile strength (psi) 90,000 - 100,000
Yield strength (psi) 65,000 - 75,000
Elongation in 2” (%) 15 - 25
Reduction of area (%) 30 - 40
Brinell Hardness (BHN) 180 - 210