Square tubes are classified by section shape:

1. Simple cross-section square tube: square square tube, rectangular square tube.

2. Complex cross-section square tubes: flower shaped square tubes, open shaped square tubes, corrugated square tubes, and special-shaped square tubes.

Surface treatment classification:

According to surface treatment, square tubes are divided into hot-dip galvanized square tubes, electrogalvanized square tubes, oiled square tubes, and pickled square tubes.

Usage classification:

Square tubes are classified by use: square tubes for decoration, machine tool equipment, mechanical industry, chemical industry, steel structure, shipbuilding, automobile, steel beams and columns, and special purposes.

Wall thickness classification:

Rectangular tubes are classified by wall thickness: ultra thick wall rectangular tubes, thick wall rectangular tubes, and thin wall rectangular tubes.