Mold Size Classification: Small, Medium, and Large Molds
Molds are generally classified as small, medium, or large based on their overall dimensions (length × width × height) and weight. While there is no strict international standard, the industry typically follows these classifications:
- Small Molds
- Medium Molds
- Large Molds
- Very Large Molds
What is Mold Size Classification?
Mold size classification is a system used to categorize molds based on their dimensions, specifically the size of the mold cavity, the tonnage of the injection molding machine required, and the type of parts they are designed to produce. This classification helps manufacturers choose the appropriate mold for their specific needs, ensuring compatibility with the injection molding machine and the desired production goals.
Small Molds
Small molds, in particular, are designed to produce smaller parts, often with high precision and fine details. They are classified based on the mold cavity size, the tonnage required for the molding machine, and the complexity of the molded part.
✅ Size Range: ≤ 400mm × 400mm
✅ Weight Range: ≤ 500kg
✅ Typical Applications:
Electronic device casings (e.g., phone cases, earphone shells)
Small plastic components (e.g., gears, connectors, plugs)
Medical device parts
Cosmetic bottle caps, small containers
✅ Mold Base Size: Usually ≤ 600mm × 500mm
✅ Compatible Injection Molding Machines: Small-tonnage machines (typically 50–200 tons)
Medium Molds
✅ Size Range: 400mm × 400mm to 800mm × 800mm
✅ Weight Range: 500kg to 2.5T (2500kg)
✅ Typical Applications:
Automotive interior parts (e.g., dashboard panels, door armrests)
Medium-sized home appliance casings (e.g., rice cookers, hair dryers, humidifiers)
Industrial plastic parts (e.g., instrument panels, toolboxes)
✅ Mold Base Size: Usually around 700mm × 1000mm
✅ Compatible Injection Molding Machines: 200–800 tons
Large Molds
✅ Size Range: 800mm × 800mm to 1500mm × 1500mm or larger
✅ Weight Range: 2.5T (2500kg) or more, up to 20T or beyond
✅ Typical Applications:
Automotive exterior parts (e.g., bumpers, dashboards, headlamp housings)
Large home appliances (e.g., washing machines, air conditioner casings)
Industrial plastic parts (e.g., pallets, trash bins, large storage boxes)
✅ Mold Base Size: Usually 1200mm × 1500mm or larger
✅ Compatible Injection Molding Machines: 800–4000 tons
Size-Based Classification
| Category | Mold Size (L × W) | Weight | Typical Applications | Injection Molding Machine Tonnage |
| Small Mold | ≤ 400mm × 400mm | ≤ 500kg | Electronics, medical parts, small plastic components | 50–200 tons |
| Medium Mold | 400mm × 800mm | 500kg – 2.5T | Automotive interiors, home appliances, industrial parts | 200–800 tons |
| Large Mold | 800mm × 1500mm | ≥ 2.5T | Automotive bumpers, large home appliances, industrial parts | 800–40 |
These classifications serve as a general guideline. The actual mold size also depends on factors such as mold structure, wall thickness, and the number of cavities.
