52100 Tubing & Bar


52100 Tube & Bar Standard Bearing Steel Air-melt ASTM A295 AMS 6440 - 300°F (149°C) -


52100 is a high-carbon chromium alloy steel, which, because of its versatility, is used in a variety of mechanical applications. In the annealed condition this steel is comparatively easy to machine, yet very high hardness and abrasion resistance can be developed by heat treatment to make the steel particularly suitable for applications requiring extreme wear resistance. In addition, 52100 alloy steel can be heat treated to high levels of tensile strength and fatigue strength.

Comparison to other materials

Tool Steels - Compared with tool steels in general, 52100 is less expensive and is much easier to handle. It is easier to form and machine than most tool steels yet can, after simple heat treatment, develop many of the properties of tool steels.

Carburizing Grades - Compared with the carburizing grades of alloy steels, 52100 sacrifices some machinability but in return the user has a material with a much more simple and inexpensive heat treatment that minimizes distortion.


Anti-Friction Bearings comprise a majority of the components manufactured from 52100 steel. Typical applications are:

  • Anti-Friction Bearings
  • Rollers
  • Slitting Rolls, Spacers and Knives
  • Knife Blades and Cutlery
  • Forming Rolls
  • Guides
  • Collars
  • Pins
  • Spindles
  • Precision Instrument Parts
  • Collets
  • Stamping Tools
  • Gears
  • Seals
  • Bushings
  • Sleeves
  • Cylinder Liners
  • Dies
  • Gages
  • Molds
  • Machine Tool Components
  • Tools
  • Thrust Collars
  • Engine Parts
  • Hydraulic Parts
  • Pump Parts
  • Clutch Faces
  • Disintegrater Rolls

Steel quality

The steel from which 52100 tubing is produced is made in electric furnaces using special refining techniques, which insure maximum cleanliness and freedom from objectionable microscopic non-metallic inclusions. This steel is made to conform to the stringent chemical and cleanliness requirements of ASTM A295 and AMS 6440. The modified grades meet ASTM A485.

Characteristics of 52100 alloy steel tubing

In addition to 52100, two modifications have been developed with increased hardenability. Together, these three grades offer a wide range of hardenability suitable for nearly any application requiring high hardness throughout thin to heavy sections. These analyses are as follows in order of increasing hardenability:

Chemical Composition
52100 ASTM A485-Grade1 ASTM A485-Grade3
Carbon 0.93-1.05 0.90-1.05 0.95-1.10
Manganese 0.25-0.45 0.90-1.20 0.65-0.90
Phosphorus 0.025 max 0.025 max 0.025 max
Sulphur 0.015 max 0.015 max 0.015 max
Silicon 0.15-0.35 0.45-0.75 0.15-0.35
Chromium 1.35-1.60 0.90-1.20 1.10-1.50
Copper 0.30 max 0.30 max 0.30 max
Nickel 0.25 max 0.25 max 0.25 max
Molybdenum 0.10 max 0.10 max 0.20-0.30
Aluminum 0.050 max 0.050 max 1.10-1.50
Oxygen 0.0015 max 0.0015 max 0.0015 max
Titanium 0.0050 max 0.0050 max


52100 alloy steel tubing is generally furnished in the spheroidized annealed condition with maximum Brinell Hardness Number 207 for hot-finished or turned tubing, and 248 for cold-drawn tubing; roto-rocked tubing may exhibit a Brinell Hardness up to 331. As furnished, each finish is in a condition for optimum machinability for its type, and for maximum uniformity after heat treatment. The long spheroidizing anneal may decarburize the exposed OD and ID tube surfaces to depths controlled by ASTM A295. This shallow decarburized surface must be removed in machining.

52100 is recommended for through hardening by oil quenching in sections up to 0.5 inch. For sections over 0.5 inch it may be necessary to water-quench for full hardness. In order to eliminate the necessity of water-quenching and subsequent danger of distortion or cracking, two modifications have been developed for oil quenching, ASTM A485-Grade 1, which is recommended for sections 0.500 to 0.750 inch, and ASTM A485-Grade 3 for sections from 0.750 to 1.500 inch.


AMS 6440



ASTM A485 (for modified grades)

Size ranges

These grades of tubing are furnished in the four size ranges of finishes shown below:

Type OD
52100 Tube OD Ranges

Cold Drawn or Roto-rocked

Hot Rolled

0.777" - 2.708"

1.932" - 11.500"

52100 Bar Diameter Ranges

Cold Drawn

Rough Turned

Hot Rolled

Forged & Turned

0.130" - 2.750"

1.000" - 2.875"

3.000" - 9.500"

10.000" - 15.500"