8844-Architectural Facts 6/19/01 3:23 PM Page 3 DESIGNER HANDBOOK STAINLESS STEEL ARCHITECTURAL FACTS Stainless Steel The Value Option® . 8844-Architectural Facts 6/19/01 3:23 PM Page 4 WHY DESIGN IN A STAINLESS STEEL? D Stainless steel is a series of steel A corollary of stainless’ high life alloys which includes at least 10.5 per- expectancy is the ease with which it can a cent chromium. Most grades used in be maintained. In an urban or industrial f architecture also include a percentage of atmosphere all that is generally needed a nickel, and manganese, molybdenum, is a washing with detergent and water or w or other elements may be added for spe- with one of the commercial stainless steel v cial characteristics. Because of its cleaners. This can often be handled in a appearance, strength and high corrosion the course of the regular window wash- c resistance, stainless steel is finding ing operation. In many circumstances, t increasingly wide use in architecture for however, washing can be left to the e both exterior and interior applications. action of rain and wind, with no fear that This fact sheet has been prepared to the metal will deteriorate. Savings that give architects and architectural students accrue from the low cost of maintaining h most of the basic data they will need to stainless can make up any difference in t put stainless steel to work effectively. cost that may appear between compo- e The fact sheet provides information on nents made of stainless and other materi- b the characteristics of the metal, the forms als. Result: in the long run, stainless is in which it is available, alloys and finishes one of the most economical of architec- most commonly specified for architec- tural metals. Rising to a height of 630 feet, Jefferson National tural purposes, and suggestions on Expansion Memorial in St. Louis, Mo., is faced with design and maintenance. The Specialty Steel Industry of North Type 304 stainless steel plates with a polished finish. Stainless steel has certain inherent America has a life cycle costing com- Because of stainless’ resistance to corrosion and advantages that make it ideal for a wide puter diskette program available free of weathering, the gleam of the catenary arch, visible charge that will compare stainless with for over 30 miles, will be permanent. variety of architectural applications. Chief among these is its resistance to corro- other materials. Architect: sion. Under normal conditions, stainless Stainless steel is produced in virtually Eero Saarinen. is unlikely to corrode, pit, tarnish, or all standard metal forms and sizes, plus deteriorate in any other way. There is no many special shapes. Sheet and strip need to compensate for loss of strength stainless are the products most often The Specialty Steel Industry of North due to deterioration, and replacement formed into architectural components. America (SSINA) and the individual costs are virtually non-existent. The designation strip is used for widths companies it represents have made From the esthetic viewpoint, stainless of metal less than 24 inches, while sheet every effort to ensure that the information is notable for its inherent beauty and the refers to 24 inch and greater widths. presented in this handbook is technically ease with which it blends with other Sheet and strip forms are available in correct. However, neither the SSINA nor materials. It has a subtle sheen which practical architectural thicknesses from its member companies warrants the does not overwhelm or intrude on other .010 inch and up (or as low as .001 inch accuracy of the information contained in design and color elements; rather, it for special applications). Heavier plate this handbook or its suitability for any complements, reflects and highlights sur- material is also available, over 10 inches general and specific use. The SSINA rounding materials. Because of its corro- in width and 3/16 inch and over in assumes no liability or responsibility of sion resistance, its appearance is perma- thickness. any kind in connection with the use of nent, and there is no danger of corrosion Stainless steels are also produced in this information. The reader is advised products streaking or staining other the form of tubing—round, oval, square, that the material contained herein materials. rectangular and hexagonal, both welded should not be used or relied on for any Stainless is among the strongest of and seamless. Welded tubing is made specific or general applications without metals. Tensile strengths of 75,000 to up to 30 inches in diameter, seamless up first securing competent advice. 125,000 psi (or higher if needed) often to 8 inches. Other available forms allow the use of gauges much lighter include bars and rods of similar shapes than are usually needed in other metals. as well as wire and extrusions. Cover: Sturdy design elements, fabricated from Society Tower, Cleveland, OH thin sheets of stainless, can combine The Society Tower project has a penthouse covered light weight with strength. in panels of stainless steel, making the roof a distinc- tive cap. The panel system consists of 22-gauge stainless steel for both the exterior and interior. Most panels have a pattern which was applied by Rigidized Metals Corporation of Buffalo, NY. The customer was Flower City Architectural Metals, Glen Cove, NY, and the panels were manufactured by E.G. Smith of Pittsburgh, PA. Architect: Kendall/Heaton Associations, Inc. and Cesar Pelli & Associates 11/98 5M 1 8844-Architectural Facts 6/19/01 3:23 PM Page 5 ALLOY TYPE DESIGNATIONS 304 is the basic chromium-nickel 316 offers more corrosion resistance 430 is a chromium ferritic stainless austenitic stainless steel and has been through the addition of molybdenum. steel with lower corrosion resistance than found suitable for the widest range of This type is desirable where severe corro- the 300 series. It is principally employed applications in all kinds of architectural sion conditions exist, such as heavy for interior use. work. It is the most readily available in a industrial atmospheres and marine l variety of forms. This type is easy to form environments. 305 and 410 are used for bolts, nuts, and fabricate with excellent resistance to screws, and other fasteners. corrosion from exposure to weather. It is 316L is a low carbon variation of 316. the grade which is normally used for It is sometimes specified where extensive exterior architectural applications. welding of heavy sections will be done. 304L is a low carbon variation of 304 having slightly higher corrosion resis- tance. It is sometimes specified where extensive welding of heavy sections will - be done. PRODUCT FORMS Dimensions Item Description Thickness Width Diameter or Size Sheet Coils and cut lengths: 3 Mill finishes Nos. 1, 2D & 2B under ⁄16" (4.76 mm) 24" (609.6 mm) & over — Pol. finishes Nos. 3, 4, 6, 7 & 8 " " " all widths 3 Strip Cold finished, coils or cut lengths under ⁄16" (4.76 mm) under 24" (609.6 mm) — Pol. finishes Nos. 3, 4, 6, 7 & 8 " " " all widths 3 Plate Flat rolled or forged ⁄16" (4.76 mm) & over over 10" (254 mm) — Bar Hot finished rounds, squares, 1 octagons and hexagons ——⁄4" (6.35 mm) & over 1 1 Hot finished flats ⁄8" (3.18 mm) to ⁄4" (6.35 mm) to — 8" (203 mm) incl. 10" (254 mm) incl. Cold finished rounds, squares, 1 octagons and hexagons ——over ⁄8" (3.18 mm) 1 3 Cold finished flats ⁄8" (3.18 mm) to ⁄8" (9.53 mm) to — 1 1 4 ⁄2" (114 mm) 4 ⁄2" (114 mm) Wire Cold finishes only: (In coil) Round, square, octagon, 3 3 hexagon, flat wire under ⁄16" (4.76 mm) under ⁄8" (9.53 mm) — Pipe & Tubing Several different classifications, with differing specifications, are available. For information on standard sizes consult your local Steel Service Center or the SSINA. 1 Extrusions Not considered “standard” shapes, but of potentially wide interest. Currently limited in size to approximately 6 ⁄2" (165.1 mm) diameter, or structurals. M 2 8844-Architectural Facts 6/19/01 3:23 PM Page 6 THICKNESS OF STAINLESS STEEL USED IN S ARCHITECTURAL APPLICATIONS Approximate Weights (in pounds per sq. foot)*** black bars U.S. indicate edge Nominal Standard thickness Thickness Gauges of Gauges in Inches END USES 5.906 10 .141 .141 5.250 ➛ 11 .125 Door bumpers, bent framing, etc. * † STREET LEVEL APPLICATIONS 4.594 column covers, fascia 12 .109 panels, mullions, pilasters—stiffened ➛ with braces, but not Column covers, interior, completely backed up where bumping by crates, baggage, etc. is not expected 3.281 14 .078 Roll-formed long, 2.625 ➛ Roofing for large self-supporting ▼ 16 .063 buildings, braced members panels but not backed up 2.100 18 .050 ABOVE STREET Formed and braces LEVEL APPLICATIONS ▼ Curtain walls, for stiffness, 1.575 spandrels, mullions supported at edges 20 .038 1.312 ➛ Window sills for 22 .031 commercial buildings Backed up by 1.050 ➛ ▼ Cleats, clips, etc. other material 24 .025 0.787 ➛ Roofing standing seam 26 .019 ➛ Gutters, leaders, exposed 28 0.656 .016 flashing, residential roofing ➛ Concealed flashing 32 0.426 .010 ***Type 300 Cr-Ni Series P M 3 8844-Architectural Facts 6/19/01 3:23 PM Page 7 SHEET FINISH DESIGNATIONS The SSINA has a handbook available free of charge on the “Finishes for Stainless Steel.” Unpolished Finish A dull finish produced by hot rolling to the specified Polished Finish A general purpose bright polished finish obtained with a 120-150 (Rolled) thickness, followed by annealing and descaling. No. 4† mesh abrasive, following initial grinding with coarser abrasives. No. 1† Polished Finish A soft satin finish having lower reflectivity than No.