.The different methods of identifying ferrous metals and alloys

. state how non ferrous metals and alloys are identified

A fitter has to handle different types of metals in his  work. A knowledge about how to recognise and differentiate the commonly used metals will help him in many ways.

Ferrous metals and alloys can be identified by

Their appearance (colour, texture etc,)

Their weight (light or heavy )

The sound

Cold hammering

The spark test (grinding )

Apart from the above tests steel bars are also identified by the code colours painted on them.

Different colours are marked, based on the different composition of materials and grade. Colours charts are available to determine the different metals.

Most non ferrous metals and alloys can be identified by their colour.

copper colour is distinctive red colour

Aluminum colour is  dull  white

Lead colour is bluish grey colour

Tin colour is silvery white, with a slightly yellowish tinge

Brass colour is distinctive yellow colour

Bronze colour is colour between copper and brgiven


Characteristics of different ferrous metals and alloys given

Low carbon steel

The appearance is smooth scale with blue/black sheen/silver grey. The density and weight is 7.85 medium weight. The sound (drop  a 15 to 25 cm long, on to the ground ) is medium metalic sound. The cold hammering is flattens easily. The spark test is stream of  yellow white sparks varying in length slightly fiery.

Medium carbon steel

The appearance is smooth scale black sheen. The density is 7.85 and weight is medium weight. The sound is higher note than that of low carbon steel. Cold of hammering is fairly difficult to flatten. The spark test is yellow  sparks shorter than those of low carbon steel, finer and more feathery.

High carbon steel

The appearance is rougher scale black. The density of metal is 7.85 and weight is medium weight. The soundof metal is good ringing sound. The cold hammering is difficult to flatten. The spark test is sparkless bright, starting near grinding wheel and more feathery with secondary branching.

High speed steel

The appearance of metal is roughness scale black with reddish tint. The density of metal is 9 and the weight is comparatively heavy. The sound of a metal is lower ringing more like low carbon steel.. The cold hammering is very difficult to flatten tends to crack easily. The spark test is faint red streak ending in fork.