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4140 Annealed (LPA) Cold Drawn Steel Bar

Annealed, cold drawn 4140 steel bar is a medium carbon, chromium-molybdenum steel with high hardenability. It is softened from the mill structure, to a pearlite structure, prior to cold drawing. This improves the ductility and can help improve machinability. Eaton Steel Bar Company stocks many diameters of 4140 LPA cold drawn steel to meet the market demand. ASTM specifications are generally applicable for cold drawn 4140 LPA steel bars.

4340 cold-rolled-steel-bar


Typical applications for this grade of steel include bolts, shafts, gears, couplings and tools.


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

  • ASTM A108
  • ASTM A322
  • JDM QL-2 certified

Shapes and Sizes

Eaton Steel Bar Company supplies 4140 LPA cold drawn steel bar in a variety of sizes ranging from – 5/6”-6”. The shapes available for this grade include:

  • Rounds

***Minimum Total Quantity Per Order is 10,000 lbs.***

Estimate Your Order Weight


Standard "4140 Annealed (LPA) 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
Chromium 0.80-1.10
Molybdenum 0.15-0.25


Estimated Mechanical Property Ranges for "Grade 4140 Annealed"

Tensile strength (psi) 95,000 - 105,000
Yield strength (psi) 85,000 - 95,000
Elongation in 2" (%) 15 - 25
Reduction of area (%) 50 - 60
Brinell Hardness (BHN) 200 - 230