3A21 Aluminum Sheet

3A21 aluminum sheet is a domestic aluminum-manganese series rust-proof aluminum alloy plate (old grade LF21), containing 1.0%-1.6% manganese, with strong corrosion resistance, good processability, easy welding (argon arc welding is preferred), stamping, and bending. The tensile strength is about 110-160MPa, and heat treatment cannot be strengthened. Common thickness is 0.3-6mm, and the state is divided into O (soft state), H14/H18 (semi-hard to full hard), etc.

3A21 aluminum sheet has excellent processing adaptability and supports a variety of precision processing technologies:

1. Cold processing

- Stamping: The ultimate stretching ratio can reach 2.3, suitable for manufacturing kitchen utensils, containers and other deep stamping parts

- Bending: The minimum bending radius is 1.5T (plate thickness), and the rebound angle is controlled within 2°

- Spinning: Wall thickness reduction rate ≤70%, suitable for cylindrical parts processing

2. Special welding process

- TIG welding: ER5356 welding wire is used, and the weld strength coefficient is ≥0.85

- Laser welding: power 3-5kW, welding speed 1.5-3m/min

- Stir friction welding: Especially suitable for connecting thick plates above 6mm

3. Precision machining

- CNC milling: cutting speed 200-300m/min, surface roughness Ra1.6μm

- Drilling: recommended speed 800-1200rpm, feed rate 0.1-0.2mm/r

4. Surface treatment technology

- Chemical polishing: using phosphoric acid-nitric acid system, the surface roughness can be reduced to Ra0.4μm

- Anodizing: film thickness 10-25μm, hardness HV300-500

- Sandblasting: use 120-240 mesh glass sand, Sa2.5 cleanliness

5. Heat treatment process

- Annealing: 340-400℃ insulation for 2-4 hours to completely eliminate processing stress

- Stabilization: 150-180℃ insulation for 6 hours to improve dimensional stability

1. Customizable according to customer needs;

2. Mature processing technology, price has great advantages compared with other aluminum coil manufacturers;

3. It has 6 semi-continuous casting production lines, 10 continuous casting and rolling production lines and 44 other large-scale processing equipment, with an annual output of 1.4 million tons;

4. The monthly output can reach 10,000 tons.

The 32 international customers we cooperated with gave high praise to 3A21 aluminum plate. A Japanese ship manufacturer gave feedback: "No corrosion in seawater environment for 5 years, fully meeting DNV GL certification requirements." German chemical equipment manufacturers particularly recognized its welding performance: "MIG welding pass rate increased from 85% to 98%, greatly reducing rework costs." Southeast Asian food machinery manufacturers praised: "FDA-certified materials fully meet hygiene standards, and the surface polishing effect exceeds 304 stainless steel." 80% of customers gave 5-star ratings in the repurchase survey, and were particularly satisfied with its: 1) Stable mechanical property fluctuations ≤3%; 2) Accurate thickness control (±0.02mm); 3) Zero damage rate of sea transportation packaging. A European engineering company has been purchasing for 8 consecutive years, with a cumulative usage of more than 15,000 tons.