81030 Special Finishes Final - SSINA: Specialty Steel ...

1 DESIGNERHANDBOOKFOR stainless STEELS pecial Finishes 81030 Special Finishes Final 3/27/00 10:21 AM Page 2 Finishes IN GENERALThe surface finish on a piece of stainless Steel sheet as produced by a mill or supplied by a Steel service center is generally the result of processing to bring the sheet product to a Final dimension. The resulting finish is usually a rolled (or unpolished) finish, either dull or bright. Several creative rolled Finishes have been developed for aesthetic applications. They add texture or simulate other Finishes , for example, polishing or abrasive blasting. Subsequent operations, such as grinding, polishing, buffing, blasting, colorizing and etching can be utilized to create a wide variety of Special Finishes (left to right)FLOOR PLATE; POLISHED BACKGROUND WITH A GOLD PAINTED ETCHED PATTERN; ROLLED FINISH SIMULATING ABRASIVE BLASTING; WOVEN stainless Steel AND COPPER CLOTH; AND AN EMBOSSED Specialty Steel Industry of North America gratefully acknowledges the assistance of Catherine M.

2 Houska, Technical Marketing Resources, Inc., Pittsburgh, Pennsylvania, consultant to the Nickel Development Institute, Toronto, Special Finishes Final 3/27/00 10:21 AM Page 3 INTRODUCTION designation, by thetrade name or designation for proprietary Finishes . The Specialty Steel Industry of North America has a designer handbook Finishes for stainless Steelwhich details the standard industry Finishes (Nos. 1, 2D, 2B, 3, 4, 6, 7 and 8 plus Bright Annealed, andMill-buffed). This handbook is designed to provide a sampling of the Special Finishes that can be obtained in today s Finishes in this brochure are not described in the ASTM standards.

3 Information about the standard mill and polished Finishes described in the ASTM standards can be found in SSINA s Designer Handbook: Finishes for stainless finish is an important factor in any specification or purchase order for stainless Steel regardlessof the intended end use. For those applications where appearance is important, finish is adesign element and must be specified. The choice of finish should never beleft to the supplier, and the specification should never be a looselyworded description such as type 304 with a brushed finish or embossed finished. The finish should beproperly identified by either thestandard industry 81030 Special Finishes Final 3/27/00 10:22 AM Page 43 Rolled Finishes are created when a stainless Steel coil is passed through a set of rolls.

4 The finish on the rolls is transferred to the surface of the coil. They are directional and, if panels are not installed in the samerolling direction, a checkerboard appearance can result. To prevent this problem, the rolling direction should be marked on the back of the panel. Dirt and debris accumulation is greater when directional Finishes areinstalled with a horizontal grain coining, one roll is smooth and theother is textured. The process creates alight, raised, one-sided pattern andstrengthens the stainless Steel throughwork hardening. This increases itsimpact resistance, reduces the depth ofscratches, and often makes it possible touse a thinner gauge.

5 Numerous patternsexist but the most popular mimic fabricslike linen. Coined Finishes are used frequently on building exteriors toreduce gauge requirements and provideimproved visual flatness. They are alsopopular in high traffic areas becausethey minimize scratches and provideimproved impact resistance. Other applications include roofing, furniture,elevator panels, and kitchen refrigeratordoors, cabinets, and can be combined with electro-chemical color and paint. When theraised areas are buffed to remove color,the remaining color is protected fromscratching and the resulting finish hasperformed well in high traffic is similar to coining exceptthat both rolls have raised interlockingpatterns.

6 When the stainless Steel coil ispassed through the rolls, a deeper, two-sided pattern is created. Because moremetal is displaced, there is a higherlevel of work hardening and a greaterincrease in strength. The pattern depthdetermines the increase in strength,impact, and scratch resistance. Withdeep patterns, it is sometimes possibleto make more substantial decreases inthickness requirements or sustain higherlevels of impact. Like coined patterns,embossed Finishes can be combined with Special Finishes Final 3/27/00 10:23 AM Page 5 ILLUSTRATED Finishes :(above left )EMBOSSED;(across bottom, left to right)TWO COINED SAMPLES;ABRASIVE BLASTED APPEARANCE; EMBOSSED; (above right)EMBOSSED,PAINTED AND BUFFED; AND(far right)EMBOSSED,ELECTROCHEMICAL COLOR,AND Special Finishes Final 3/27/00 10:24 AM Page 6 POLISHED APPEARANCES everal stainless Steel producers havedeveloped rolled Finishes that mimic the look of a No.

7 3 or No. 4 polish or a hairline finish. Because these finishesare applied to the coil in the mill, theyare less expensive than polished can be one or two-sided. Theirimpact resistance is similar to that ofother flat Finishes . They will hide minorscratching that is in the same directionas the polish pattern. Blending andrepair of minor damage is possible forsome of these Finishes . ABRASIVE BLASTEDAPPEARANCES everal companies have developed non-directional rolled Finishes that mimicthe appearance of abrasive Finishes generally provide betterflatness and uniformity and are morecost effective than abrasive blastingsheet or strip.

8 They are applied in thesame manner as coined or embossedfinishes and can be either one or two-sided. Because they do not have asmuch cold work or the raised patternsof the coined and embossed Finishes ,they do not hide scratches. Their impactresistance is similar to other flat have been used for roofing, wallpanels and other applications but aregenerally not used in high traffic are susceptible to Finishes :(above left)EMBOSSED,ELECTROCHEMICALLY COLORED, BUFFED; AND(below) Finishes (continued) 81030 Special Finishes Final 3/27/00 10:24 AM Page 7 stainless Steel can be colored by electrochemical coloring, sputtering, plating, and resin-based scratch resistance, appearance, and color stabilityof these processes varies considerably and should betaken into consideration during selection.

9 Althoughsome of these processes improve corrosion resistance,this should not be considered a substitute for selecting an appropriate grade of stainless Steel for the Electrochemical coloring (also calledlight interference or INCO coloring) isachieved by immersing pieces in a hotacid solution and applying an electricalcurrent. This thickens the transparentchromium oxide film, which makesstainless Steel corrosion resistant andchanges the way light is reflected bythe surface. A full spectrum of colors isavailable including gold, bronze, purple,blue, red, black, and green. The color willnot fade and can be applied uniformly or varied for a rainbow effect.

10 There willbe slight variations in the color is transparent, thefinish beneath it is visible. Differentcolor and finish combinations createunique effects. Color can be removedselectively by etching, polishing orengraving. Fingerprints are visible butcan be removed from smoother may become permanent when rough Finishes are color can be damaged by scratching and is not repairable. Whenthe color is applied over a coined orembossed finish and the raised areas are buffed, the remaining color isrecessed and protected and has performed well in high traffic areas. SPUTTERED COLORS puttering is sometimes referred to asplasma vapor deposition (PVD).