Mechanical Engineering


It is a method of joining two similar or dissimilar metals by means of fusible alloy or metals called solder. The melting point of filler metal is below 450°C. It is used for obtaining a leak proof joint or a low resistance electrical joint.

Soldering is of two types.

Soft soldering: It is used is sheet metal works for joining parts which are not bearing excessive loads.

Hard soldering: It is used where a stronger joint is required.

In soldering process lap joints are preferred. The composition of some of the solders is listed below.

S. No. Type of solder Lead (%) Tin (%)
1. Soft solder 37 63
2. Medium solder 50 50
3. Electrician solder 58 42
4. Plumber’s solder 70 30