SAND CASTING

WHAT IS SAND CASTING?

Sand casting is a versatile manufacturing process used to create metal parts by pouring molten metal into a sand mould.

The process begins with the creation of a pattern, representing the final shape and dimensions of the part, which is then placed in a two-part sand mould. Once the mould is prepared, the pattern is removed, leaving behind a precise impression of the desired part. Molten metal is poured into the mould cavity, where it solidifies and takes on the shape of the part. After cooling, the sand mould is broken apart to reveal the metal casting inside.

At A & M Manufacturing Company Ltd. Our associated sand casting foundries are capable of producing a wide range of metal parts, from small components to large machinery parts, and can be used with both ferrous and non-ferrous metals. Examples of parts produced using this technique include engine blocks, cylinder heads, gears, pulleys, and ornamental metalwork.

SAND CASTING PROCESS

1. Pattern Making
The first step is creating a pattern that represents the shape of the desired casting. Patterns are typically made from materials like wood, metal, or plastic and are designed to be slightly oversized to compensate for metal shrinkage during cooling. The pattern includes allowances for machining and draft, facilitating its removal from the mould.

2. Mould Making
The mould is made by packing special moulding sand around the pattern in a moulding box, known as a flask. The moulding sand is mixed with clay and water or other bonding agents to help it retain its shape. The process involves two halves of the mould: the cope (top half) and the drag (bottom half). The pattern is placed in the drag, and sand is packed around it. Then, the cope is placed on top, and sand is packed into it as well. Once the sand has been compacted, the pattern is carefully removed, leaving a cavity that mirrors the shape of the pattern.

3. Core Making
If the casting requires internal cavities or undercuts, cores made of sand are used. These cores are formed in separate core boxes and are positioned in the mould cavity before the molten metal is poured. They remain in place during casting to form the internal features of the part.

4. Melting and Pouring
The metal, which can vary from iron, steel, aluminium, bronze, and more, is melted in a furnace to a specific temperature. Once the metal reaches the desired temperature and is thoroughly molten, it’s carefully poured into the mould cavity. Pouring must be done at a controlled rate to avoid turbulence and splashing, which can create defects in the casting.

5. Cooling
After the molten metal has been poured, it begins to cool and solidify within the mould. The cooling time can vary based on the metal used and the size of the casting. It’s crucial to allow the metal to cool completely to ensure the integrity and strength of the casting.

6. Mould Breakaway
Once the metal has solidified, the sand mould is broken apart to release the casting. This step is irreversible; moulds made from sand are destroyed during the casting removal, meaning a new mould is needed for each casting.

7. Cleaning and Finishing
The casting is then cleaned of any sand, scale, and excess metal from the gates, runners, and risers used to channel the molten metal into the mould. Cleaning can involve processes like shot blasting, grinding, and cutting. Further finishing processes, such as machining, painting, or coating, may be applied to achieve the desired surface finish and dimensional accuracy.

8. Inspection
Finally, the casting undergoes various inspections for quality assurance, including dimensional accuracy, surface finish, and structural integrity. Non-destructive testing methods such as X-ray, ultrasonic, or magnetic particle inspection may be used to detect internal defects.

SAND CASTING ADVANTAGES

Sand casting offers several advantages:

Versatility: It can produce parts of various sizes and complexities, ranging from a few grams to 100 tons, making it suitable for a wide range of applications across industries.
Cost-Effectiveness: The process is relatively inexpensive compared to other casting methods, especially for low to medium volume production runs, as it requires simple equipment and materials.
Material Variety: This technique can be used with a wide range of metals and alloys, including ferrous materials such as stainless steel, iron, carbon steel, and alloy steel, as well as non-ferrous materials including aluminium, bronze, brass, zinc, and more, offering versatility in material selection to meet specific application requirements.
Tooling Flexibility: Patterns can be made from various materials and are relatively easy to produce and modify, allowing for quick adjustments and iterations during the design process.
Large Part Production: Sand casting is capable of producing large and heavy parts that may be impractical or costly to produce using other methods.
Low Production Time: Sand casting has a relatively short lead time, making it suitable for rapid prototyping and production of parts with tight deadlines.

A & M MANUFACTURING SAND CASTING CAPABILITIES

Our foundries in China are fully equipped with advanced sand casting equipment, including automated moulding lines, Disamatic green sand moulding machines, 3D sand printing systems, robotic handling systems, and sand reclamation systems. Together with our experienced engineers, we provide comprehensive sand casting services from tooling design to quality inspection.

Capable of producing high-quality sand castings ranging from 200g to 100 tons, we have served customers across various industries for over 30 years. These industries include railway systems, automotive, agriculture machinery, building construction machinery, oil & gas industries, and many more.

At A & M Manufacturing Company Ltd, all volumes are welcome, and our Chinese foundries can produce up to 10,000 tons of sand castings annually. Due to the nature of this casting technique, production lead times are relatively quick compared to investment casting. Depending on the order quantity, the production lead time, including tooling design and mass production, could be as short as a few weeks.

WHY A & M MANUFACTURING COMPANY LTD?

Designing and Manufacturing Toolings: Our skilled engineering team is proficient in designing and manufacturing tooling to suit a variety of sand casting requirements, ensuring precise and efficient production processes.
Mass Production: Utilising advanced production facilities and equipment, we have the capacity to mass-produce sand casting parts and components of various sizes and complexities, meeting the demands of diverse industries and applications.
Rigorous Product Quality Inspection: We prioritise quality assurance and offer rigorous product quality inspection processes to ensure that all components meet our customers’ exacting standards and specifications, providing peace of mind and reliability.
Providing Flexible Supplying Options: In addition to our manufacturing capabilities, we offer flexible supplying options, including UK stockholding facilities, to accommodate varying customer needs and preferences, facilitating efficient logistics and timely delivery.

EXCELLENCE IN DIVERSE INDUSTRIES - OUR MASTERY OF SAND CASTING SOLUTIONS

A & M Manufacturing Company Ltd specialises in sand casting for diverse industries, crafting durable and complex parts. Here are some classic examples:

Automotive: Crafting engine blocks, cylinder heads, manifolds, and transmission cases using metals like aluminum and cast iron for their strength.
Machine Tools: Producing heavy machinery and industrial equipment parts, such as housings, gears, and large frames, thanks to sand casting’s ability to handle large, complex shapes.
Pipes and Fittings: Making cast iron pipes and fittings for water and drainage systems, leveraging sand casting for its efficiency and versatility in sizes.
Construction: Creating durable and aesthetic elements like lamp posts, bench ends, and architectural features, all suited to withstand environmental pressures.
Marine: Manufacturing corrosion-resistant parts like propellers, anchors, and engine housings, utilizing bronze and similar materials.

Our work across these sectors demonstrates the adaptability and quality of sand casting in producing essential components.