The "standard" finishes for stainless steel most widely used are those designated for sheet. These are identified by a system of numbers, the "unpolished" or rolled finishes being #1, #2D, #2B, #2BA, and the "polished" finishes being #3 and #4. Most of the Chromium-nickel steels have a single-phase structure, which is essentially non-magnetic in the annealed condition and are not hardenable by heat treatment. Cold working develops a wide range of mechanical properties and the steels may become slightly magnetic in the cold worked condition.
#1 - a coarse, dull surface which results from annealing and pickling after hot rolling to the specified thickness. Surface is not smooth and has no reflectivity. Applies to all plate and hot rolled products.
Unpolished or Rolled Finishes
#2D - a matte finish which results from cold rolling followed by annealing and pickling. This produces a silvery white but nonlustrous surface. This finish offers a minimum degree of reflectivity. The dull, somewhat open finish retains lubricants well and is quite sutable for deep drawing operations. For strip products, the equavalent designation is a #1 finish.
#2B - a bright, cold rolled finish, a product of the same production process as #2D finish except that the annealed and pickled sheet receives an additional final light rolling pass through the rolls. This finish offers moderate to good reflectivity. The #2B finish is used for all but the most diffuclt forming operations and it is more readily polished than the #2D. For strip products, the equivalent designation is a #2 finish.
Special Finishes
Bright annealed - This is the most highly reflective finish stocked by Mokes Steel, but it does not quite approach mirror like quality. The finish is developed through careful cold rolling and then pressuring the bright finish by passing it through a controlled atmosphere annealing furnace from which oxygen has been excluded. This finish is used primarily as trim or accent styles and is almost always specified in the narrower strip widths and coil form.
Polished or Ground Finishes
#3 - This is an intermediate polished surface obtained by grinding the flat rolled stainless teel with an abrasive belt, approximately 100 mesh. The surface is smooth and not as reflective as a #2B finish and is generally used where a semi-reflective polished surface is required that is not required to be pit-free. Should the finish be damaged during fabrication, it may be restored through the use of a hand grinder with an approximately 100 grit abrasive.
#4 - This is a finer, slightly more reflective finish than #3 and is developed in the same manner except that an approximate 120 to 150 mesh grinding belt is normally used. This is a general-purpose, pit-free bright finish with a visible "grain" which breaks up a mirror reflection. Repairs to finish damaged may be accomplished in the same manner as for the #3, expect with a finer belt or wheel is used.
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