b'COLD-FORMED STEELCold-formed SteelUnderstanding the difference between gauge and sheet steel thicknessesT he cold-formed steel industry has been advisedwasmadetoobtainacloserapproximationfor against using the term gauge to specify sheetinterchangeabilitybetweenweightandthickness. steel thicknessyet it still appears in practice andOver a long period of time, this value for sheets has construction documents to this day, in certain segmentsbeen found to be close to 2.5-per-cent heavier than more than others. Simply put, gauges can refer to a range40.80 lb/ft 2 /in. A figure of 41.820 lb/ft 2 /in is the one ofsteelthicknessesandmayvaryfromonesuppliercommonly used to express the relationship between to another. To help clarify this ongoing confusion, theweight and thickness for steel sheets.Canadian Sheet Steel Building Institute (CSSBI) published atechnicalfactsheet(Facts10-12)thatexplainstheThe Galvanized Sheet Gaugedifferences in terminology and provides a helpful gauge- TheGalvanizedSheetGauge(GSG)isanolder to-thickness equivalency chart. Users are advised that milssystem used primarily by the trades consuming non-are often used as an alternative unit to inches within thestructural galvanized steel and is a measure of the Imperial measurement system: 1 Mil = 0.001. zinc-coated sheet thickness. It was developed in the early days of galvanizing before sophisticated wipers Sheet Steel Gauges and Thicknesses were available and, consequently, zinc thicknesses Withintheconstructionindustry,thereisoftenwere thicker than today. The GSG system was used confusionovergauges,gaugenumbersandtheon some of the older gauge charts published years related thickness. The industry has been trying toago that are unfortunately still used even today.move away from gauge numbers, without complete success.ThefollowinginformationwillshowwhyThickness DefinitionssheetsteelproductsshouldbespecifiedtotheThere are a number of terms used for sheet steel decimal thickness. products that need to be explained because they will affect the thicknessofproductthatcouldbe Manufacturers Standard Gauge for Steel Sheets delivered to the job site.The most common gauge system used in Canada for structural sheet steel products is the ManufacturersNominal Thickness: When sheet steel is produced Standard Gauge (MSG).The MSG for steel sheetsby the steel companies, it is manufactured to a target wasdevelopedhavingaDEFINITETHICKNESSornominalthickness. As with all manufacturing equivalent for each gauge number. In the standardprocesses,variationsinthefinalthicknessofthe gauge system, the density of steel is taken as 489.6sheetareunavoidable.However,thethicknessis lbs/ft 3 ,or40.80lbs/ft 2 /in.However,sincesheetcontrolled very tightly to ensure that it does not fall weights are calculated on the basis of specified widthbelow the minimum thickness (as described below).and length, with all shearing on the over side, and also since sheets are somewhat thicker at the centreBaseSteelThickness: Thethicknessofthesheet thantheyareattheedges,afurtheradjustmentsteel material without any coatings.12|SUMMER 2025 ADVANTAGE STEEL'