Polished Premium Low Thermal Expansion Graphite Casting Ingot Mold for Metal Casting

Product Description

Product Description

What is a graphite ingot mold?

In gold refineries, jewelry manufacturing facilities, and metal recycling companies, molten metal must be cast into ingots of uniform size and with smooth surfaces to facilitate weighing, marking, storage, transportation, and trading. 

Graphite ingot molds serve as the forming vessels for this process: when molten metal is poured into the preheated mold cavity, the graphite rapidly absorbs heat, allowing the metal to solidify uniformly with minimal shrinkage; once cooled, the intact ingot can be easily removed from the mold.
 

Compared to cast iron and steel molds, graphite molds conduct heat more rapidly, do not crack under rapid cooling or heating, allow for demolding without tapping, and do not introduce impurities into high-purity metals-which is precisely why graphite molds are widely used in the casting of refining-grade gold and silver ingots.

 

Why Choose Ningheda's Graphite Ingot Molds?

Jiangxi Ningheda New Material Co., Ltd. is located in the Fengxin Industrial Park in Yichun, Jiangxi. The company possesses full-chain production capabilities-ranging from graphite grinding, molding, and calcination to further processing-as well as an ISO 9001 quality management system. Our ingot molds are not modified versions of off-the-shelf parts; instead, they are custom-made to meet our customers' specific processes through the entire workflow-from material selection → groove design → CNC machining → inner wall polishing → final inspection:

Traceable Materials: We use isostatic fine-grain graphite such as NX604 and NX605 and refuse to use recycled graphite, ensuring purity and batch consistency from the source;

Mold Cavity Design Based on Ingot Weight: Tell us the weight of the ingots you need to cast, and we'll calculate the mold cavity dimensions, draft angles, and fillet radii to ensure smooth demolding and well-formed ingots;

Precision interior finishing: CNC milling combined with manual refinement ensures a high surface finish in the mold cavity, resulting in ingots with smooth surfaces and sharp edges, thereby reducing the need for post-casting polishing;

Tested thermal endurance: Materials with a density of ≥1.85 g/cm³ and compressive strength of ≥70 MPa, combined with an optimal wall thickness design, can withstand high-frequency casting cycles.

 

Cavity Layouts and Specifications

Based on casting output and ingot requirements, Ningheda offers a variety of cavity layout options:

Single-cavity mold: Suitable for casting large-sized ingots, such as 1 kg, 2 kg, and 3 kg gold or silver ingots; cavity dimensions can be customized according to customer drawings.

Two-cavity molds: Suitable for medium-volume production; two ingots can be cast in a single pour, improving operational efficiency.

Three-cavity/four-cavity molds: Suitable for jewelry workshops and small refineries, balancing output and flexibility.

Six-cavity/nine-cavity molds: Suitable for batch casting of small-sized ingots, such as 100g and 200g gold or silver ingots; multiple ingots can be cast in a single operation, significantly improving production efficiency.

 

Cavities can be machined into rectangular, circular, oblong, or square shapes. The inner walls are finely polished to achieve a low surface roughness, allowing the metal to shrink naturally and release from the mold after cooling without the need for a release agent.

Product Features

Feature Terms	Parameters
Material	NX604 / NX605 Isostatic (Fine-Grained) Graphite
Bulk Density	≥1.85 g/cm³
Compressive Strength	≥70 MPa
Number of slots	1 / 2 / 3 / 4 / 6 / 8 / 12 / 16 slots (customizable)
Applicable Spindle Weight	100 g - 50 kg (designed to customer specifications)
Applicable Metals	Gold, silver, copper, aluminum, zinc, tin, lead, and their alloys
Operating Temperature	We recommend preheating to 200-300°C before use.
Accuracy	CNC machining, dimensional tolerance ±0.1 mm
Surface	Precision milling and polishing of the mold cavity, Ra ≤ 25 μm

Our Advantages

Multi-chamber single-pour casting doubles casting efficiency-the 16-chamber/12-chamber design enables the production of an entire sheet of low-weight ingots (such as 10 g/20 g gold bars) in a single pour, eliminating the need for repeated casting and handling in single-chamber setups, making it ideal for refineries with high daily output;

Crack-Resistant Design for Large Ingots-Molds for 1-3 kg ingots feature thickened walls and transition fillets, combined with high-flexural-strength materials, to withstand thermal shock during high-flow casting of copper and aluminum;

Non-Stick Molds, No Release Agent Required-Graphite's self-lubricating properties allow silver and gold bars to be easily removed with a light tap after cooling, without damaging the ingot surface or leaving graphite residue;

No metal contamination, guaranteed purity-High-purity graphite is chemically inert and does not react with gold, silver, copper, or aluminum, ensuring ingot purity meets refining requirements;

 

Customizable non-standard channel shapes-Square, rectangular, circular, and other shapes can be machined, supporting customer brand customization (OEM/ODM);

 

Minimum order of 1 piece, with a lead time of 7-25 days-low prototyping costs, stock production for standard specifications, and rapid delivery upon confirmation of custom drawings.

 

Application

 

Applications	Demonstration of Strengths
Precious Metal Refining (Gold, Silver, Platinum, etc.)	Guaranteeing the Highest Purity: No impurities are introduced, ensuring the value and purity of the precious metals.
Jewelry Manufacturing and Casting	Improving the Quality of Finished Products: The smooth surface of the cast ingots facilitates subsequent processing and reduces material waste.
Non-ferrous Metal Casting (Copper, Aluminum, Zinc, etc.)	Highly efficient and durable: Withstands repeated thermal cycles in large-scale production, reducing overall operating costs.
Metal Recycling and Reuse	Cost-effective: Recycled mixed metals are smelted into standard ingots to maximize their value.
Laboratory Research and Analysis	Precise and Reliable: Provides high-purity experimental samples for scientific research, ensuring the accuracy of data.

 

 

Packaging & Shipping

Moisture protection is the top priority during transportation: Graphite is porous and easily absorbs moisture; if a mold becomes damp and is then subjected to sudden heat, it may crack. Each mold is first vacuum-sealed or hermetically sealed in plastic film.

 

Cushioning and Reinforcement: Each individual mold is fully wrapped in foam or bubble wrap. When stacking multiple molds, cushioning pads are placed between layers to prevent corners from being knocked during transport (graphite edges are brittle, and impacts can create starting points for future cracks);

 

Export Crating: The molds are packed in plywood crates suitable for long-distance transport by sea or air; small-batch samples can be shipped via international express;

 

Lead Time: 7-15 days for standard specifications; 15-25 days for custom specifications after drawings are confirmed;

 

Storage Instructions (included with shipment): Upon receipt, store in a dry, well-ventilated environment (recommended temperature: 5-25°C, humidity: 50-60%). Place the product on a wooden pallet at least 20 cm above the ground to avoid direct contact with concrete floors, and periodically rotate the stack to prevent moisture buildup.

 

FAQ

Q1: This is our first collaboration. Can you design a mold cavity based on my target ingot weight? What information do I need to provide?

A: Yes, we can. Please provide the target ingot weight (e.g., a 1 kg gold ingot), the type of metal, and photos or drawings of the existing ingot dimensions. If you do not have drawings, we can calculate the mold cavity dimensions based on the ingot weight and an estimated density, then provide drawings for your approval before machining.

 

Q2: Do graphite ingot molds need to be preheated before use?

A: We recommend preheating the mold to 200-300°C before pouring. Pouring molten metal directly into a cold mold causes excessive thermal shock, which shortens the mold's service life; ingots cast from a preheated mold also have better surface quality.

 

Q3: Which metals are suitable for casting in this graphite ingot mold?

A: This mold is suitable for the vast majority of precious metals and non-ferrous metals, including gold, silver, red copper, brass, pure aluminum, and aluminum alloys. It is chemically stable, does not react with molten metal, and does not contaminate the metal raw materials.

 

Q4: What are the common specifications for graphite ingot molds?

A: Common specifications are categorized by ingot weight into 100g, 200g, 500g, 1kg, 2kg, 3kg, etc., with cavity dimensions determined by the required ingot shape. For example, the cavity of a 1kg gold ingot mold measures approximately 100×50×30mm, while a single cavity in a multi-cavity 100g gold ingot mold measures approximately 50×25×15mm. Specific dimensions can be customized according to customer requirements.

 

Q5: Can a mold with minor damage be repaired?

A: Superficial scratches and small chipped edges can be corrected through machining; however, if through-cracks are present, replacement is recommended to prevent bursting during casting, which could result in metal loss and safety hazards.

 

Q6: Why do my graphite ingot molds crack or even burst after a few uses?

A: Cracking is typically caused by two factors: thermal shock and moisture absorption.

Uneven heating (thermal shock): The mold must be preheated before use. If molten metal is poured directly into a cold mold at room temperature, the extreme temperature difference will cause the mold to crack. Please preheat it to 100°C or higher.

Internal moisture: Graphite has microporosity and absorbs moisture from the air. If the mold is damp and not thoroughly dried before pouring, the internal moisture will instantly vaporize and expand, causing the mold to burst. Be sure to store the molds in a dry environment and ensure they are completely dry before use.

 

Q7: Can you provide samples? What is the lead time?

A: We can usually provide free samples for you to inspect the quality, but you will be responsible for the shipping costs. For large or high-value samples, a basic cost fee will be charged. Sample lead time is approximately 3-10 days. Lead time for bulk orders is typically 7-25 days after payment, depending on the order quantity and customization requirements.

 

Q8: How do I request a quote?

A: Please provide accurate information regarding dimensions, quantity, and material requirements. We will respond with a quote within 24 hours. For urgent quotes, please call us directly.

 

If you need a custom graphite ingot mold with specific weight per unit area, dimensions, or number of cavities, simply provide the type of metal used, ingot dimensions, or production requirements. 

We will match you with the appropriate materials and mold solutions free of charge and quickly provide an accurate quote.
 

Contact Information

Get a sample and quote for Graphite Ingot Mold today

Telephone: [phone]

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Address: No. 966 Tiangong South Avenue, High-Tech Industrial Park, Fengxin County, Yichun, Jiangxi, China

Ningheda Carbon - A one-stop provider of high-temperature sintering solutions, from graphitization to precision machining