How To Create a No.4 Stainless Steel Finish

No. 4 Finish Stainless Steel is the workhorse of the light fabrication industry. This general-purpose finish is widely used for restaurant and kitchen equipment, storefronts, handrails, food processing and dairy equipment. No. 4 is the easiest of the stainless finishes to maintain.

Recommended steps for creating or blending a #4 finish on stainless steel.

Step #1 LEVELING THE WELD (choose one of the following options)

  • Preferred’s Firestorm Fiber Sanding Disc – 60 grit (7 x 7/8″ arbor hole 60 Grit #37529*) use with 7″ medium back-up pad #50410.
  • Preferred’s Firestorm Flap Disc – Type 27 60 grit (7 x 7/8″ arbor hole 60 Grit #10965FF**)

** Made with our Firestorm ceramic grain for fast stock removal and long life. Includes a grinding aid for cooler running temperatures and less loading.  Ultra-fast stock removal and longest life.

Tip: Start with 60 grit or finer & use 7″ grinder if possible. (The grind lines from 7″ diameter discs are easier to blend than small radius grind lines left by 4-1/2 or 5″ diameter discs.) Align the grind line scratches with the grain line direction of the original stock. (Perpendicular scratches are more difficult to blend while parallel scratches are easier to blend.)

Step #2 SETTING THE GRAIN (choose one of the following options)

  • Preferred’s Firestorm abrasive sanding belt 120 grit (3-1/2 x 15-1/2″ 120
    grit #70696-C3*) Note: mount on expandable drum sander sold by other sources.
  • Preferred’s Firestorm abrasive No Lap Spiral Band 120 grit (2 Dia. x 1″ Wide
    120 Grit #77416-C3*) use with rubber drum (2 x 1 x 1/4 – #50547).
  • Preferred’s Firestorm Mounted Flap Wheel 80 grit (3″ x 1″ x 1/4″ 80 Grit
    #11391-C3*)

Made with our original Firestorm ceramic grain for fast cut and long life.
Includes a grinding aid for cooler running temperatures and less loading.

Tip: Stay as close as possible to the weld area to minimize the time spent on final blending.

Step #3 FINAL FINISHING – choose one of the following options.

  • Preferred’s Surface Conditiong Belt (A-Med) (3-1/2 x 15-1/2″ A-Med #53789)
    Note: mount on expandable drum sander sold by other sources.
  • Preferred’s Surface Conditioning No Lap Spiral Band (A-Med) (2 Dia. x 1″ Wide
    A-Med #534955), use with rubber drum (2 x 1 x 1/4 – #50547).

Step #4 FINAL BLENDING / TOUCH-UP

  • Preferred’s Black Flex-N-Finish Hand Pad 6 x 9 (#07446)

Tip: Use these flexible hand pads with a sanding block for final blending and touch-up.