Sand & Special Casting

Overview

PUNI offers a complete range of sand casting and special casting processes for larger parts that fall outside investment casting's practical size range. From medium-sized valve bodies to heavy machinery housings up to 500 kg, our foundry delivers consistent quality across all production volumes.

Process Options

• Resin-coated sand (覆膜砂): Excellent dimensional accuracy and surface finish, ideal for medium-to-large complex castings
• Green sand: Economical choice for high-volume production of simpler geometries
• Dry sand: Used for very large castings and complex internal cavities
• Lost foam (EPC): Pattern-less casting for complex shapes with no parting line
• Centrifugal casting: Dense, defect-free parts for cylindrical components like bushings and pipes

Capability Range

• Weight per piece: 1 kg to 500 kg
• Maximum dimension: 1500 × 1000 × 800 mm
• Dimensional tolerance: CT8-CT10 per ISO 8062
• Surface roughness as-cast: Ra 12.5 - 25 μm
• Annual capacity: 3000+ tons

Equipment List

• Resin sand mixing lines with automated moulding
• Green sand moulding lines (DISA matchplate and flasks)
• Lost foam moulding station with steam vaporisation
• Centrifugal casting machines (horizontal and vertical, 50-2000 kg)
• Heat treatment furnaces up to 12 m³
• Sand reclamation system for closed-loop operation

Materials We Cast

• Gray iron: HT200, HT250, HT300 (for machinery bases and housings)
• Ductile iron: QT400-18, QT450-10, QT500-7, QT600-3, QT700-2
• Austempered ductile iron (ADI) for wear-resistant applications
• Carbon steel and low-alloy steel castings per GB, ASTM, EN standards
• Wear-resistant steel: high-chrome cast iron, manganese steel
• Heat-resistant steel for furnace and kiln applications

Typical Applications

Pump bodies and impellers (water pumps, slurry pumps, chemical pumps), valve bodies and bonnets for industrial pipelines, gear blanks and hubs for transmission systems, machinery bases and housings, heavy-duty wear parts for mining and cement industries, and custom-engineered castings per customer drawings.

Our Strengths

• Full moulding capability from small batch to high-volume production
• In-house heat treatment for normalised, quenched and stress-relieved conditions
• Advanced lost foam capability for complex shapes without draft angles
• Pattern storage for repeat orders — patterns maintained for minimum 3 years
• Direct shipping to your machining supplier or in-house CNC completion available

Quality Standards

All castings dimensionally inspected using CMM and traditional gauges. UT, MT and PT testing available on request per ASTM E138 / E709 / E165. Material certificates and heat treatment records retained per batch for full traceability.