Sand Casting

Views: 10     Author: Site Editor     Publish Time: 2021-11-25      Origin: Site

Sand Casting

Cast Iron & Steel Sand Casting Foundry

Sand casting uses green sand (moist sand) or dry sand to form the molding systems. The green sand casting is the oldest casting process used in history, while the dry sand casting could be divided into lost foam casting and vacuum casting. When making the mold, the patterns made of wood or metal should be produced in order to form the hollow cavity. The molten metal then pour into the cavity to form the castings after cooling and solidification.

The are several sand casting process based on different mold materials. At Densen Group sand casting foundry, we can proceed the sand casting process by green sand casting, pre-coated resin sand casting and furan resin sand casting. The pre-coated resin sand casting is also called shell molding casting or shell casting, which has much better surface for the finished castings than green sand castings.

Capacities and Molten Metal for Sand Castings

In our high tech facilities, we offer both automatic sand molding machine and manual molding operations in our resin sand casting processes. As an iron and steel foundry, Densen Group can pour iron castings using our no-bake casting process up to 1 ton finished weight in gray iron castings and ductile iron castings, and up to 0.5 tons in steel castings and stainless steel castings. Densen Group can produce casting parts in a wide variety of materials, including grey iron, ductile iron, stainless steel, carbon steel, alloy steel based on different standards from China and overseas. Densen Group is dedicated to the quality of our work, and our commitment to excellence ensures the highest customer satisfaction. As a global leader in high precision, high complexity, and mission critical casting and machined metal parts, we strive to meet and exceed the needs of our customers.


▶ Materials for Sand Casting at Densen Group's Foundry

Grey Cast Iron:  EN-GJL-100, EN-GJL-150, EN-GJL-200, EN-GJL-250, EN-GJL-300, EN-GJL-350 or Their Equivalent Grades

Ductile (Nodular) Cast Iron: EN-GJS-400-18, EN-GJS-40-15, EN-GJS-450-10, EN-GJS-500-7, EN-GJS-600-3, EN-GJS-700-2, EN-GJS-800-2 or Their Equivalent Grades

Cast Aluminium and Their Alloys

Cast Steel or other materials and standards on request


▶ Capabilities of Sand Casting moulded by hand: 

Max Size of Casting Molds: 1,500 mm × 1000 mm × 500 mm

Weight Range of Sand Castings: 0.5 kg - 500 kg

Annual Capacity of Sand Castings: 5,000 tons - 6,000 tons

Casting Tolerances: On Request or According to ISO 8062


▶ Capabilities of Sand Casting by Automatic Molding Machines: 

Max Size of Casting Molds: 1,000 mm × 800 mm × 500 mm

Weight Range of Sand Castings: 0.5 kg - 500 kg

Annual Capacity of Sand Castings: 8,000 tons - 10,000 tons

Casting Tolerances: On Request or According to ISO 8062


Sand Casting Inspection Capabilities

Our Spectrometer checks 15 chemical elements and metallurgical microscope produces high-resolution images 1,000 times magnified, and our cleanliness meter determines particle size and quantity to ensure materials meet or exceed the international standard. Densen Group use ultrasonic detectors to discover flaws, and have X-ray machines and accelerators that can scan castings with 200 mm maximum wall thickness.



Densen Group has a full range of inspection capabilities in house, which include: 


Spectrographic and manual quantitative analysis

Metallographic analysis

Brinell, Rockwell and Vickers hardness inspection

Mechanical property analysis

Low and normal temperature impact testing

Cleanliness inspection

UT, MT and RT inspection



Steps of Sand Casting Process


Making Pattern.Patterns made of wood, resin (plastic) or aluminium could be used to produce during the sand casting. Generally, the costs of the aluminum patterns will be the highest, but it is the most suitable process if the customers need thousands of sand castings with higher dimensional tolerances and better surface quality.

Sand Casting Molding Process.The resin sand will be mixed by the sand treatment equipment, then shoot into the sand boxes (flasks). The molding workers will guarantee the sand can be filled to all positions, and make the sand as solid as possible.

Self-Hardening of Resin Sand Mold. After molding by workers, the sand is still loose. Then, the sand mold will be coated by a type of alcohols based coating, after burning, the resin sand mold will become very solid. This is why this casting process is called as hard mold casting process, also called as self-hardening sand mold.

Melting and Pouring. Just like the sand casting process, medium frequency electrical furnaces are used to melt irons for resin sand casting process.

Sand Blasting, Cleaning and Grinding. The shot blasting process is to remove the sand and oxides outsite of the sand casting parts, then the workers will cut off the gating systems, and grind the gating positions and parting lines. Finally, the rough castings will be completed. If secondary processes like machining or surface treatment are needed, these complete castings will be taken to the next workshops.


Sand Casting Foundry Gallery

In Densen Group's foundry, we utilize the professional equipment to assemble the automatic sand casting production lines. We have two production lines for sand casting, the vertical automatic sand casting line and the horizontal automatic sand casting line. These highly organized equipment help us to produce the sand castings part of high quality and big volume. These equipment can cast a diverse materials such as grey iron casting, ductile iron casting, carbon steel, alloy steel, stainless steel, aluminium and brass.