Primary processing makes usable material; secondary processing makes parts
Primary processing makes usable material; secondary processing makes parts
Primary processing converts raw resources into usable materials and common supply forms. Secondary processing turns those materials into parts or products. Stock means material supplied for further work, such as sheet, rod, boards or pellets.
- Metal
- Ore is refined into metal and made into stock such as sheet; sheet is then cut and bent into a bracket.
- Plastic
- Chemical feedstocks are made into polymer resin, often supplied as pellets; pellets are then molded into a bottle cap.
- Wood
- Logs are sawn into lumber; boards are then cut, joined and finished as furniture.
- Glass
- Mineral ingredients are melted and made into sheet glass; sheets are then cut and edge-finished for a window.
These terms describe a material's place in the supply chain. They do not replace the five process categories: sawing a log and sawing a furniture part are both separating.
Why the boundary needs context
Different industries draw the primary/secondary boundary differently. Here, use the raw-resource-to-stock and stock-to-part distinction. Extraction supplies the raw resource; mining alone does not turn ore into an ingot. A supplier's finished product can also be the next manufacturer's starting material.