Metals7 entries

Metals Database

Steels, stainless and non-ferrous alloys with density and the property classes each is normally supplied in.

Overviewwhat this group covers and how to read the numbers

Metal is the default choice for a fastener, and the decision usually comes down to two things: how much load the joint carries, and what the joint will be exposed to. A property class answers the first; the alloy family answers the second.

Density is what turns a drawing into a weight, and it is remarkably uniform across the steels — carbon, alloy and stainless all sit within a few percent of each other. Switching from steel to aluminium is what moves the number, cutting it to roughly a third.

The property class figures alongside each material describe heat-treated alloy steels. They have no meaning for brass, aluminium or titanium in this list, which are supplied against their own designations rather than a tensile class.

steel2 entries

stainless2 entries

non-ferrous3 entries

Density comparisonevery metals entry on one scale

Weight calculator
MaterialGroupDensity (g/cm³)kg/m³
Aluminiumnon-ferrous2.72700
Titaniumnon-ferrous4.514510
Carbon Steelsteel7.857850
Alloy Steelsteel7.857850
Stainless Steel A2 (304)stainless7.97900
Stainless Steel A4 (316)stainless88000
Brassnon-ferrous8.58500

Densest entry: Brass at 8.5 g/cm³. Lightest: Aluminium at 2.7 g/cm³.

Common applicationswhere these materials are actually used

AutomotiveAerospaceAerospace structuresArchitectural fixingsAutomotive suspensionChemical plantCladdingCoastal constructionDecorative hardwareElectrical terminalsFood processing equipmentGeneral fasteningHeavy machineryHigh-preload jointsInstrumentationMachineryMarineMarine hardwareMedical implantsMotorsportPlumbing fittingsPressure vesselsSanitary fittingsSheltered marineStructural steelworkSwimming pool fixingsWeight-critical assemblies

Frequently asked questionsabout metals selection

Which metal should I choose for outdoor use?

Stainless A4 (316) where chlorides are present — coastal air, salt water, swimming pools — because the molybdenum addition resists pitting that A2 will not. Inland, A2 (304) is normally sufficient and costs less. Plain carbon steel needs a coating and even then will not match either.

Why is aluminium not always the lightest option for a fastener?

Its density is about a third of steel, but its permissible load is far lower, so a joint of the same strength needs a larger aluminium fastener — which eats much of the weight saving. It also corrodes galvanically against steel, so the two should not be mixed without insulation.

What is the lightest metal in this database?

The density comparison above ranks every metal in this list and names the lightest and heaviest, so the answer stays correct as entries are added.

Do all these metals use the same property classes?

No. The numbered classes such as 8.8 and 10.9 describe quenched and tempered steel bolts to ISO 898-1. Stainless uses its own designations (A2-70, A4-80) and non-ferrous metals such as brass and aluminium are supplied against material designations instead.

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