Class B StressProof® A311 Cold Finish Steel Bar
Chemical Composition
Carbon:                0.40%-0.48%
Manganese:          1.35%-1.65%
Phosphorus:          0.040% Max
Sulphur:               0.24%-0.33%
Silicon:                0.15%-0.35%
Tensile Strength: 115,000 psi (Min)
Yield Strength:    100,000 psi (Min)
Elongation:         8% (7% Min above 3 in)
Typical Uses
Typical uses for A311 Class B StressProof® include:
  • Arbors
  • Keyed Shafts
  • Motor Shafts
  • Splined Shafts
  • Drive-Shafts
  • Armature Shafts
  • Gears
  • Sleeves
  • Lead Screws
  • Link Pins
  • Collets
  • Bushings
  • Boring Bars

A311 Cold Finish Bar - Class B StressProof®

A311 Class B StressProof® Cold Finished Steel Bar is produced using a proprietary process that draws the bar through a special die under heavy draft. A311 Stressproof® Bar is a medium carbon free machining steel. The bar is then stress relieved in a precisely controlled furnace. The result is a steel bar product that meets stringent standards that provide a wide variety of benefits, including:
  •     Improved wearability without case hardening
  •     Strength without heat treating
  •     Exceptional surface quality
  •     Excellent machinability
  •     Extended tool life
  •     Resistance to fatigue and stress
  •     Balanced working
  •     Minimized warpage and distortion
  •     Controlled low stresses
Alro also stocks:
A311 Class B StressProof® TG&P

StressProof® is electro-magnetically tested using eddy currents. Although it also can be induction hardened, it should be watched for quench cracks.

StressProof® is a trademark of the LaSalle Steel Corporation.