Cold-Formed Steel Construction

The term cold-formed steel construction, as used in this section, refers to structural components that are made of flat-rolled steel. This section deals with fabricated components made from basic forms of steel, such as bars, plates, sheet, and strip. COLD-FORMED SHAPES Cold-formed shapes usually imply relatively small, thin sections made by bending sheet or strip steel in roll-forming machines, press brakes, or bending brakes. Because of the relative ease and simplicity of the bending operation and the comparatively low cost of forming rolls and dies, the cold-forming process lends itself well to the manufacture of unique shapes for special purposes and makes it possible to use thin material shaped for maximum stiffness. The use of cold-formed shapes for ornamental and other non-load-carrying purposes is commonplace. Door and window frames, metal-partition work, non-loadbearing studs, facing, and all kinds of ornamental sheet-metal work employ such shapes. The following deals with cold-formed shapes used for structural purposes in the framing of buildings. There is no standard series of cold-formed structural sections, such as those for hot-rolled shapes, yet although groups of such sections have been designed (‘‘Coldformed Steel Design Manual,’’ American Iron and Steel Institute, 1101 17th St., NW, Washington, DC 20036). For the most part, however, cold-formed structural shapes are designed to serve a particular purpose. The general approach of the designer is therefore similar to that involved in the design of built-up structural sections. Cold-formed shapes invariably cost more per pound than hot-rolled sections. They will be found to be more economical under the following circumstances:
1. Where their use permits a substantial reduction in weight compared to hotrolled sections. This occurs where relatively light loads are to be supported over short spans, or where stiffness rather than strength is the controlling factor in the design.
2. In special cases where a suitable combination of standard hot-rolled shapes would be heavy and uneconomical.
3. Where quantities required are too small to justify the investment necessary to produce a suitable hot-rolled section.
4. In dual-purpose panel work, where both strength and coverage are desired.

—–8.1 Material for Cold-Formed Steel Shapes
—–8.2 Utilization of Cold Work of Forming
—–8.3 Types of Cold-Formed Shapes
—–8.4 Some Basic Concepts of Cold-Formed Steel Design
—–8.5 Structural Behavior of Flat Compression Elements
—–8.6 Unstiffened Cold-Formed Elements Subject to Local Buckling
—–8.7 Stiffened Cold-Formed Elements Subject to Local Buckling
—–8.8 Application of Effective Widths
—–8.9 Maximum Flat-Width Ratios of Cold-Formed Steel
—–8.10 Unit Stresses for Cold-Formed Steel
—–8.11 Laterally Unsupported Cold-Formed Beams
—–8.12 Allowable Shear Strength in Webs
—–8.13 Concentrically Loaded Compression Members
—–8.14 Combined Axial and Bending Stresses
—–8.15 Welding of Cold-Formed Steel
—–8.16 Arc Welding of Cold-Formed Steel
—–8.17 Resistance Welding of Cold-Formed Steel
—–8.18 Bolting of Cold-Formed Steel Members
—–8.19 Self-Tapping Screws for Joining Sheet Steel Components
—–8.20 Special Fasteners for Cold-Formed Steel
—–8.21 Steel Roof Deck
—–8.22 Cellular Steel Floor and Roof Panels
—–8.23 Corrugated Sheets for Roofing, Siding, and Decking
—–8.24 Lightweight Steel Metric Sheeting
—–8.25 Stainless Steel Structural Design
—–8.26 Characteristics of Preengineered Steel Buildings
—–8.27 Structural Design of Preengineered Buildings
—–8.28 Design of Open-Web Steel Joists
—–8.29 Construction Details for Open-Web Steel Joists