What is Gauge or Metalwork?

Gauge refers to the thickness of the metal.

This site gives some information, but it is in the IPS system not metric.

http://www.engineersedge.com/gauge.htm

This is a luminaries specification.

If the luminaries "body" is less than 20 gauge (thickness of the sheet steel) the unit will be lighter weight which may cause premature wear and tear or failure of the fixture depending on the application.

This is what the manufacturer will use to manufacture the luminaries to the specification.

If luminaries bodies of less than 20 gauge are furnish/supplied this will most likely result in the owner/architect/engineer rejection of the luminaries due to non compliance of the specification.

JKS,

Gauge is used in the US, isn't it? But as I remember that gauge is a unit of electric cable cross section? Does it have any connection to the gauge here? 1 gauge here = ?? mm.

Take a look here

And here

http://en.wikipedia.org/wiki/Wire_gauge

20 gauge, in sheet steel, became 1 mm thick in metric sheet manufacture. As did 20G stainless, 18G aluminium and 15 G zinc, become 1 mm

Wire and sheet gauges are different, as are ferrous and non ferrous gauges - as are American and British gauges.

See the chart here ^{_{(and be glad your metricated)}}

What gauges are different among Steel, Gal. steel, Aluminium, or Zinc? So when I said gauge, I must use an additional word implied it is for steel or aluminium?

34point5,

Sorry that I have a spelling mistake, My question is "why" not "what".

Why gauges are different among Steel, Gal. steel, Aluminium, or Zinc? So when I said gauge, I must use an additional word implied it is for steel or aluminium?

Like screw thread systems, gauges were developed in different ways, by different industries, in different countries. The main divide is ferrous and nonferrous industries. Over that is 'rival countries'. Aside from that, is material form.

The general language of specifying sheet, is gauge number and material.

E.g. in sheet; "20 gauge aluminium" or "20 gauge steel" will tell them which gauge system to use.

If you are specifying wire (in imperial) you should always nominate the gauge system. E.g. AWG (American wire gauge) or SWG (British standard wire gauge) or Stubs, or BWG

Similarly; if you are specifying in certain product areas where there could be a misunderstanding, always add the abbreviation or acronym.

Just as when specifying in metric, you should add 'mm' or 'm' to a dimension to make it clear it is not inches - particularly when dealing with the one or two countries that have not metricated.

These days, I specify in metric.

Metric equivalents to gauge systems are commonly available in gauge using countries. Many American industries are bi-lingual, or essentially metricated.

If the documentation of the job being quoted is Imperial, I will add (in brackets) the gauge number. This also serves as a 'check' both parties are using the intended gauge and system (for the material and form < e.g. sheet, wire, etcetera).

As many 'semi-technical people' get gauges wrong, metric ties up the spec. It's also a subtle way of making them check, if they don't, then freak out - say - when the weight of the lights is too much for the false ceiling - tough luck.