Alloy Steel

Peerless Steel stocks a wide selection of alloy steel grades and sizes with delivery available from three Midwest locations. No order too small, no order too large.

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Alloy Steel Grades Sizes in Stock
8620 CF Cal-Al Rounds thru 4"
8620 HR Rounds thru 18-1/4", Flats Squares and Plates thru 7" Thick
4140 CF Cal Al Ann. Rounds thru 4-1/2"
4140 DCF Ann. Flats & Squares thru 6" Thick
4140/42 HT DCF Flats & Squares thru 4-1/2" Thickness 26-32 R/C
4142 HT HR Flats, Squares and Plates thru 4-1/2" Thickness 26-32 R/C
4150 HR Ann. Mod Cal Al Rounds thru 10"
4150 HR HT Mod. Cal Al Rounds thru 18-1/4" - 26-32 R/C
4340 HR Ann. 2" thru 10"
6150 DCF Ann. Flats & Squares thru 6" Thickness
6150 HR Ann. Rounds thru 18-1/4" Flats, Squares & Plates thru 7" Thick
6150 CF Ann. Rounds thru 2"

AISI 8620 and 8620 CT Alloy Bars

A case hardening alloy that may be used where high surface strength, a tough ductile core and excellent wear characteristics are needed. It provides relatively low distortion during heat treatment and safe hardening over a wide hardness range. Cold finished bars are Calcium Treated providing better machinability and tool life then regular AISI 8620.

AISI 4140 and 4140 CT Annealed Alloy Bars

This medium carbon alloy grade is widely used for many applications requiring high tensile strength and some ductility combined with hardness in the R\C 40 range. The cold finished bars are Calcium Treated, this addition greatly increases cutting speeds and tool life without sacrificing mechanical properties.

AISI 4150 (Mod. RS) CT Annealed Alloy Bars

A modified and resulphurized chemistry of this medium carbon alloy grade provides deeper hardenability and the addition of sulphur along with Calcium Treatment results in improved machinability for many larger part sections.

AISI 4150 CT QTSR Heat Treated Alloy Bars

A modified chemistry of 4150 steel that is Quenched and Tempered to a brinnel hardness of 262 to 311. Furthermore, this product is Stress Relieved to reduce distortion during machining and may be used for many parts without further heat treatment, providing good hardness penetration, toughness and strength. The addition of calcium produces dramatic improvements in machinability and tool life, when used with carbide or high speed tooling.

AISI 6150 Annealed Alloy Bars

The 6150 grade has chromium and vanadium added to impart greater impact hardness. This grade has low distortion properties and is easily heat treated and will harden to C-55 - C-58 Rockwell range.


  • Production Cutting
  • Special Cutting
  • Flat Grinding
  • Centerless Grinding
  • Machining
  • Heat Treating, Stress Relieving, Annealing
  • Straightening
  • Special Testing
  • Deburring

Peerless checks all Alloy bars for size, quality, and condition. We maintain accurate identification of grades and heats on all steel products.