How to check which tool is good?

Many people buy tool from supermarket or retailers,and many tool will be broken when you use them first time?

everybody know the tool quality is bad.But how to know the quality before buy them? Following

NO.1  Material 

A good material is very important in a tool. SAE A325, SAE 1045，SAE 5140  are main main material in market.But only minority can check it.

NO.2  Production process

Dropped Forging, Casting,Cold upsetting are usual process.The Cold upsetting are usually used in sockets.Different production process will produce different weight.everybody only check weight,will know the quality.Dropped Forging is weight than Casting.

NO.3  Hardness

If the tool after heat treatment,the tool's hardness will be high,and max loading is high too. 

NO.4  Surface treatment

Good Brightness,Smooth surface treatment layer of tool is better.

NO.5 Size precision