Which marking medium is used to draw clear and sharp lines?

Concept:

Marking media is a substance that is applied on the surface of the metal to distinct the marked line clearly.

Marking out is the preliminary work of providing guidance lines and center before cutting and machining.

The different marking media are:

Whitewash (Chalk powder ):

• It is applied to rough forging and castings with oxidized surfaces.
• It is not recommended for a work-piece of high accuracy.

Prussian Blue:

• It is used on filed or machine-finished surfaces.
• This gives very clear lines but takes more time for drying than other marking media.

Copper Sulphate:

• The solution is prepared by mixing copper sulfate in water and a few drops of nitric acid.
• The copper sulfate is used on filed or machine-finished surfaces. It sticks to the finished surfaces well.
• It needs to be handled carefully as it is poisonous.
• Copper sulfate coating should be dried well before commencing marking as, otherwise, the solution may stick on the instruments used for marking.

Cellulose Lacquer:

• This is a commercially available marking medium.
• It is also used on the machined work surface.
• It is made in different colors and dries very quickly.