• Stainless and Engineering Steel Bar and Wire

Stainless Steel Bar 
Round Bar (mm) 3.18 to 304.8.
Angle Bar (mm) 20 to 100 section; 3.0 to 12.0 thickness.
Flat bar (mm) 12 to 150 wide; 3 to 25 thickness.
Channel Bar (mm) 80 x 40 to 150 x 75 section; 5.0 to 6.0 thickness.
Square Bar (mm) 12 to 50.8.
Grades 303, 304, 304L, 316, 316L, Improved Machining (303, 304, 316).
Finishes Cold (bright) drawn, centreless ground, hot rolled, smooth turned, peeled, slit rolled edge & hot rolled annealed.
Processing Bar cutting to 650mm.

For detail of stainless steel bar products and the Atlas range please select the relevant product group of your interest from the dropdown shown in the “Stainless and Engineering Steel Bar and Wire” menu bar.

Stainless Steel Bar
Stainless steel bar comprises numerous products referred to by the shape, the section dimension, grade, condition and surface finish.

Shapes and section dimension measurement
The following shows the variety of shapes commonly available in stainless steel bar and the dimensional designation for its shape.

Round Bar Measured across the diameter.
Angle Bar Measure leg x leg x thickness.
Square Bar Measured across the flats (AF).
Hexagonal Bar Measured across the flats (AF).
Flat Bar Measured width x thickness.
Channel Bar Measured flange x web x thickness.
Hollow Bar Measured outside diameter (OD) x inside diameter (ID).

Common Stainless Steel Bar Grades
The following are common grades available in stainless steel bar, which is not an exhaustive list and other grades may be available for specialised application. In such cases please contact your local Atlas Steels Service Centre.

303 Free-machining bar grades.
304 & 304L Standard 18/8 grades.
316 & 316L Improved resistance to pitting corrosion in chloride environments.
321 Stabilised grades for heavy section welding and high temperature applications.
253MA (S30815) High temperature resistant grade.
416 Free-machining bar grade.
431 High hardness and toughness grade, primarily for shafting.
2005 Standard duplex stainless steel – high resistance to pitting and stress corrosion.
630 (17-4PH)  High strength shafting grade.

A post production operation where heat is used to achieve a desired hardness to suit the end use application.

H&T Hardened and Tempered.
ANN Annealed.
PH Precipitation Hardened.

Surface finish
This is the surface condition of the bar, which is usually designated at the time of order. Generally, this ranges from rough hot mill finished in the case of forging bar to very smooth centreless ground in the case of engineering component bar.

CD Cold Drawn. P Polished.
BD Bright Drawn. SRE Slit Rolled Edge.
CG Centreless Ground. HF Hot Finished.
CF Cold Finished. HRAP Hot Rolled Annealed and Pickled.
P&T Peeled and Turned. RT Rough Turned/Peeled.
ST Smooth Turned. PR Peeled and Reeled.

Dimensional tolerances for bar
This is the product dimensional tolerance required by the end user and produced by the mill usually from the drawing, peeling or grinding process.

Forms and conditions: stainless steel bar

Round Square Hexagonal
Precision Ground. Cold Drawn. Cold Finished/Smooth Turned.
H8 or H9. H9. H10. H11. H11.

For further technical information on these products refer to the relevant section of the Atlas Steels Product Reference Manual. There is other technical and product information contained within the Technical Library of this website.

Stainless Steel Improved Machining Bar
Atlas Steels distributes “Improved Machining” stainless steel bar. Improved machining bar is a result of a controlled melting process, giving high chip-breaking properties and providing a self-lubricating quality through the processing of machining.

The benefits of Improved Machining grade

  • Improved machining.
  • Increased cutting speeds.
  • Lower unit cost of production.
  • Increased tool life.
  • Lower production power requirements.
  • Consistent machining characteristics.
  • Improved product surface finish.
  • Chemical composition within ASTM standards.
  • Properties the same as commercial grades of stainless steel:
    – high corrosion resistance;
    – similar mechanical properties;
    – easily welded; and
    – good formability.
  • Improved drilling and tapping characteristics.

Improved Machining grade will reduce wear on tools and extend tool life
Highly abrasive inclusions which damage tools are excluded in the IM manufacturing steel melt process. There is a decrease in flank wear and crater wear of carbide tooling which results in:

  • less dismounting and reassembling of tools;
  • less adjustment time; and
  • there is a noticeable improvement in the life of cutting tools.

Improved Machining grade will enable higher cutting speeds
To benefit fully from improved machining grade stainless steel bar and its unique characteristics minor modification is required to cutting conditions in particular, it is necessary to increase cutting speeds.