Chapter 9: Sheet Metal Practices and Layout

Overview

The branch of metalworking known as sheet metal comprises a large and important element. Sheet metal parts are used in countless commercial and military products. Sheet metal parts are found on almost every product produced by the metalworking industries throughout the world.

Sheet metal gauges run from under 0.001 to 0.500 in. Hot-rolled steel products can run from in thick to no. 18 gauge (0.0478 in) and still be considered as "sheet." Cold-rolled steel sheets generally are available from stock in sizes from no. 10 gauge (0.1345 in) down to no. 28 gauge (0.0148 in). Other sheet thicknesses are available as special-order "mill run" products when the order is large enough. Large manufacturers who use vast tonnages of steel products such as the automobile makers, switch-gear producers, and other sheet metal fabricators may order their steel to their own specifications (composition, gauges, and physical properties).

The steel sheets are supplied in flat form or rolled into coils. Flatform sheets are made to specific standard sizes unless ordered to special nonstandard dimensions.

9.1 Carbon and Low-Alloy Steel Sheets

Carbon steel sheets and coils are produced in the following grades or classes:

Hot rolled

• Low carbon (commercial quality)

• Pickled and oiled

• 0.40/0.50 carbon

• Abrasion resistant

• Hi-Form (A715), high strength/low alloy (grades 50 and 80)

• A607 specification, high strength/low alloy (INX 45, INX 50, ExTen 50)

• A606 specification, high strength/low alloy (Cor-Ten)

Note: The code numbers indicate the yield strength of the high strength/low-alloy steels; i.e., INX 45 = 45,000...