Custom Die Casting Mould

Molds in aluminum die casting shape molten aluminum into precise forms. They ensure dimensional accuracy and surface finish, crucial for high-quality mass production of intricate aluminum components.

Our Die Casting Mold Services

At YONGZHU CASTING, we draw on our extensive industry expertise to produce top-quality die cast molds.

Each mold is crafted with precision, reliability, and tailored to meet the unique specifications of our clients.

We cater to various sectors, including automotive, aerospace, electrochemical, and power tools.

By employing cutting-edge mold flow analysis techniques, we conduct virtual simulations prior to production.

This allows us to accurately visualize metal flow and refine designs before manufacturing begins.

Our commitment is to deliver high-quality die cast molds!

Table of Contents for This page

To fully understand die casting molds is not something that can be summarized in a single article. Therefore, we try to mention the complete information here. In order for you to get the information you want to know directly, you can click on the picture below and we are ready to set up the jump.

What is Die Casting Mold ?

A mold is basically a cavity or a matrix where a fluid or plastic material takes shape to become a finished product. In die casting, the mold is where molten metal gets poured in to form the product.
When you’re casting metal, you need something to hold the molten metal in the shape you want. That’s where the mold comes in—it creates the exact form for the die-cast parts. The end result is a product that perfectly mirrors the mold’s shape.
In the process, molten metal is injected into the mold at high pressure. As the metal cools, it contracts a bit and grips the core of the mold while it solidifies. Once the casting is fully hardened, it’s going to have the exact shape of the mold it was in.
Creating molds takes careful planning. If you’ve got a complicated casting design, the mold will naturally be more complex too.
To make sure everything fits perfectly, you can use 3D CAD/CAM systems. Simulation software can help adjust the mold design to make sure it’s the best fit for the die-cast parts you want to produce.
The mold’s shape is usually based on a model or pattern. This is the three-dimensional object whose form you want to replicate using the mold.

Mold design is crucial because it impacts everything—from the shape and consistency of the die-cast product to its dimensions and overall quality. If the mold isn’t designed right, you could end up with flawed castings or even material corrosion.
So, before you start making the mold, take a close look at the size and geometry of the castings you’re planning to produce. Design the mold with those factors in mind to get the best results.
Molds make it possible to produce millions of identical die-cast parts efficiently. Once a mold is properly designed, you can reuse it again and again for similar castings.
When choosing a material for your mold, make sure it’s stronger and has a higher melting point than the material you’re casting.
If not, the mold could get damaged during the process. That’s why die-casting molds are typically made from tough, durable metals.

A couple of things to keep in mind: try to keep a consistent cross-section in the mold. If you need to change the thickness, do it gradually to avoid shrinkage issues or porosity in the final product.
Also, it’s best to avoid large, flat surfaces in mold designs—they use a lot of material.
But if flat surfaces are necessary, make sure the corners are rounded. This helps with the flow of the metal and improves the appearance of the finished casting.
And don’t forget to trim down any thick or heavy sections in the mold. Otherwise, you’ll use more metal than necessary, and it’ll take longer to produce the castings.

Components of Mold

A mold is made up of two halves. The first half, often called the “A” side or the stationary half, is also known as the cavity. This part forms the external surface of the die-cast products. The second half, known as the “B” side or the moving half, is referred to as the core.

Other important components of the mold include ejector pins, lifters, the sprue, support plates, gates, runners, leader pins, and the locating ring. The ejector system, which houses the pins and lifters, is what helps remove the cast parts from the mold after solidification. The sprue acts as a passageway, channeling molten metal into the mold.

The leader pins, positioned in each corner, make sure the two mold halves align correctly during the casting process. And the gate? That’s the small opening where molten metal enters the mold cavity.

1. The Cavity

The cavity is the part of the mold responsible for shaping the outside of the die casting. This is where molten metal is poured in to take the desired shape.
Once the cavity is filled, pressure is applied to compensate for any material shrinkage, ensuring the final casting has a perfect form.
Molds can have one or more cavities. A multi-cavity mold is especially helpful when you need to increase production speed and efficiency, as it allows multiple parts to be cast at the same time.
Even though a multi-cavity mold can have different sizes and shapes, it's essential to avoid imbalances in the mold design to ensure everything runs smoothly.

2. The Core

The core forms the internal part of a casting. It’s a pre-shaped insert placed inside the mold to create features like holes or chambers that couldn’t be formed otherwise.
Cores allow for more intricate casting designs and help make complex internal shapes.
When a core is used, it can also help strengthen the mold and support the gating system.
For example, a splash core prevents erosion in the gates and runners, while a pouring basin core creates a reservoir at the top of the mold for molten metal to enter smoothly.

3. Ejector Pins

Ejector pins do exactly what their name suggests—they help push the cast parts out of the mold once they’re finished. These pins are located on the core side of the mold and are a crucial part of the ejection system, which improves production efficiency.
It’s important that the design of ejector pins is carefully tested. Any flaw in their design could cause the castings to crack or shrink, resulting in faulty products.
There are several types of ejector pins, including case-hardened, black, and toughened pins. The case-hardened pins, for example, are made extra hard and can withstand high temperatures up to 200°C.

4. The Lifter

Lifters help remove parts from the mold by moving at an angle and sliding the steel cavity away from undercuts during ejection. They are particularly useful for creating complex shapes and are used mostly for internal undercuts in die casting.
There are two main parts of a lifter: the body and the forming parts. Lifters come in different types, such as integral and non-integral. Integral lifters are compact, durable, and resistant to damage.
Lifters can also be categorized as either T-shaped or cylindrical. T-shaped lifters are often used for large die castings that require high precision, while cylindrical lifters are easier to install and maintain, making them more common in everyday applications.

5. Sprue

6. Runner

The runner is another part of the gating system. It’s a channel that directs molten metal from the sprue to the gate and then into the mold cavity.
There are two types of runners: hot runners and cold runners. Hot runners use a manifold system with heating elements to keep the material molten until it flows into the cavity, while cold runners rely on larger, unheated channels to guide the material. Cold runners are generally easier and less expensive to maintain than hot runners.

7. Gate

The gate is the opening that connects the runner to the mold cavity. It’s where the molten metal enters the cavity and takes shape.
Gates are typically placed at the thickest part of the casting to ensure even flow and strength. A good rule of thumb is to make the gate two-thirds the thickness of the casting wall to avoid material buildup.
Additionally, gates are usually placed in areas that won’t be visible on the final product because they can leave marks when removed, which might affect the casting’s appearance.

What Influences Die Casting Mold Design

1.) Draft

The draft refers to the slight angle added to the vertical walls of the mold, ensuring the die-cast parts can be smoothly ejected.
Without this taper, removing parts from the mold could become a real hassle, requiring manual effort to peel them out.
By incorporating a draft angle, we make it much easier for the part to pop out while also preventing warping after the molten metal is injected.
Another benefit is that it helps speed up production by reducing the cooling time, keeping costs down.
Plus, it ensures the parts come out smooth, scratch-free, and with a clean finish.
Incorporating draft angles early in the design stage is key—this way, you don’t have to go back and adjust the mold later on.

2.) Fillets

Instead of having sharp, abrupt edges in the mold, you can add a fillet, which creates a smooth, curved transition between surfaces. Think of it like rounding out corners that would otherwise be too sharp.
Not only does this improve the overall design, but it also eliminates stress points that could lead to cracks or damage.
Sharp corners, especially in areas where the mold’s cross-section changes quickly, can make the casting process harder.
By using fillets, you’re creating smoother, rounded edges that help avoid these issues and enhance the overall durability of the castings.

3.) Parting Line

The parting line is where the two halves of the mold meet—the stationary and moving sides.
This line dictates the way the mold opens and how the cast part will be ejected. It’s important to think of the parting line early on, as it impacts the entire casting process.
In simpler molds, the parting line might be a straightforward, central line. But for more complex molds, it could be in a less obvious location.
The key is placing the parting line where it allows smooth metal flow and easy ejection, which helps extend the mold’s lifespan and improves the overall quality of the die-cast product.

4.) Ribs

Ribs are thin, vertical features that are added to the mold to provide structural support without needing thicker walls.
They’re like built-in reinforcements that give extra strength to the mold, preventing warping or other defects.
Ribs are especially useful for adding strength to the thinner parts of the casting, and they help guide the molten metal to fill the mold more evenly.
However, ribs need to be properly sized. If they’re too tall, they can break off during casting or ejection, which can slow down production or cause defects in the final product.

5.) Bosses

Bosses are raised areas or knobs on a mold designed to serve as mounting points or fasteners.
They’re often where screws or other fasteners will go once the casting is complete. When designing bosses, it’s essential to consider the size of the hole and where to place them.
It’s a good idea to position them away from the mold’s exterior walls, using ribs to connect them to the rest of the mold structure to prevent sinking.
By ensuring bosses are well-sized and correctly placed, you can avoid defects like sink marks, which can ruin the part’s appearance and functionality.

How Does a Die Casting Mold Work?

Die casting molds are typically made up of two halves, each forming a detailed cavity.

Molten aluminum is injected into these cavities, filling every crevice to form the shape and features of your final product.

Once the aluminum solidifies, the mold is opened, and the product is removed. The molds are reusable, allowing for the same precise die-cast part to be produced over and over.

The Process Flow & Duration Estimation

While the general die-casting mold manufacturing process follows the same steps, the production cycle can vary depending on the size and specific requirements of each product. Since different products may require unique molds, we provide a clear lead time based on your specific project needs.

Step 1: Design (2-5 Days)

The first step is designing the mold based on your product’s requirements. During this phase, we collaborate with you to figure out the best solution. Several key factors are considered:

The size of the die casting and how well it aligns with the mold
Whether the mold’s design supports efficient die casting
Your product’s future demand and production requirements

Step 2: Machining (25-30 Days)

The machining process involves several steps and tools, including grinding, CNC hardening, wire cutting, and EDM (Electrical Discharge Machining). Many of these steps are repeated for precision.

While the mold frame is simpler and typically involves CNC and punching, the core requires more detailed work. Once everything is complete, the core and frame are assembled.

Step 3: Make Samples (1-3 Days)

Once the mold is fully assembled, we begin creating sample parts. The purpose of this is to test the mold’s accuracy and performance. If there are any errors or defects, the mold is taken apart for adjustments.

This process is repeated until we’re sure the mold meets all specifications. Generally, two sample attempts are enough to achieve success.

Step 4: Shipping (5-30 Days)

The time required is different depending on the mode of transport. Air freight is fast, but more expensive, sea freight is cheaper, but takes longer, you can choose according to your situation

Advantages and Disadvantages of Aluminium Die Casting Molds

	Advantages	Disadvantages
1	Improved Production Efficiency: Aluminium die casting molds significantly enhance production efficiency by allowing for rapid, repetitive casting of parts. This leads to shorter production cycles and high output volumes.	High Initial Tooling Costs: The process of designing and manufacturing molds is expensive due to the multiple steps involved, such as design, prototyping, testing, and machining. The initial investment can easily run into thousands of dollars.
2	High Quality and Consistency: Molds ensure consistent, high-quality results, especially when producing parts with tight tolerances. Every part produced has identical features, contributing to uniformity across large production runs.	Not Suitable for Small Production Runs: Due to the high initial costs, aluminium die casting molds are impractical for small-scale productions. These high costs can’t be justified for limited quantities.
3	Suitable for Medium to High-Volume Production: These molds are ideal for medium and large-scale production. The average cycle time for die casting ranges between 10-60 seconds, depending on the mold’s size and complexity. This makes it possible to produce thousands or even millions of parts quickly.	Time-Consuming to Manufacture: Creating a mold can take weeks or even months. If parts are required urgently, die casting molds may not be the most efficient solution.
4	Durability: Aluminium die casting molds are built to last, often achieving between 5,000 to 10,000 casting cycles. This means the same mold can be reused for many production runs, reducing the need for frequent replacement.	Design Limitations: Molds come with certain design restrictions. Sharp edges and undercuts should be avoided, and draft angles and radii must be incorporated for proper ejection. Changing the mold design is both difficult and costly once it is manufactured.
5	Cost Efficiency Over Time: While the upfront costs for molds can be high, they are cost-effective in the long run due to their longevity. As the mold is reused, the cost per unit drops. Furthermore, aluminium scrap from production can be recycled, adding to cost savings.

Mould Production Process

Mold Design

The first stage in mold production is designing the mold’s shape and geometry using 3D/CAD software.
Critical considerations include the cavity, core, ejector pins, lifters, sprue, gate, and runner system.
Proper draft angles should be applied to vertical walls, and sharp corners should be avoided by using fillets.
The parting line, runner system, and slender cores must be carefully designed to ensure mold longevity and ease of casting.

Mold Core and Frame Machining

Once the design is complete, machining removes excess material from the mold, shaping it to perfection.
Machining is typically done through Computer Numerical Control (CNC) or Electrical Discharge Machining (EDM).
CNC uses Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) software to create precise mold geometries, while EDM removes material using electrical discharges without directly contacting the mold.

Mold Assembly

After machining, the different parts of the mold are carefully assembled.
This requires high skill to ensure that everything fits correctly.
Proper assembly involves checking sharp edges, marking the mold base with correct dimensions, and greasing core pins, slide pins, and guide pins to prevent wear during use.

Cost Analysis

Design Cost

The design cost varies depending on the mold’s complexity. Molds with intricate shapes and features tend to be more expensive due to the detailed design process required.

Material Cost

The cost of materials for both the mold core and frame impacts the total price. For example, 45# steel is often used for mold frames, while the mold core may use higher-grade materials like Japanese H13 steel for improved durability.

Machining Cost

The machining and assembly of the mold core and frame also contribute significantly to the overall cost. Machining the core is typically more complex, involving multiple processes that add to the price.

The Basic Knowledge About Die Casting Molds

Classification of Molds

Die casting molds are categorized based on the number of cavities and their functionality:

Single Cavity Mold:
A single cavity mold contains only one cavity, producing one die-cast part per production cycle. It’s a simple and efficient option for low-volume production runs.
Multi-Cavity Mold:
This type of mold has multiple cavities of the same design, allowing it to produce several identical parts in one production cycle. It’s ideal for high-volume production as it increases efficiency and output.
Family Injection Mold:
Family molds contain multiple cavities of different designs, but all the parts are made from the same material. This allows the production of several parts in one cycle, even if they are not identical in shape or function. It’s perfect for manufacturing a set of related parts in one go.

Common Materials Used in Mold Making

Molds can be made from a variety of materials, depending on the production requirements. Common materials include:

Plaster (Gypsum)
Resin
Metal (e.g., bronze, aluminum, lead, silver, and gold)
Casting Rubber

At Yongzhu Casting, we typically use 45# steel for mold frames and Japanese-grade H13 steel for mold cores to ensure durability and optimal performance.

Mold Lifespan

The lifespan of a mold is measured by the number of production cycles it can endure. Typically, die casting molds can last between 50,000 to 100,000 cycles, depending on the material and production conditions.

Reusability of Molds

Yes, molds can be reused in die casting production. Depending on the materials and manufacturing methods, molds can handle 5,000 to 10,000 production cycles before they need to be repaired or replaced.

Why Choose Yongzhu Casting?

Automated Machinery

At Yongzhu Casting, we use advanced automated machinery to produce die casting molds. Our commitment to excellence is reflected in our continuous investment in the latest technology and production facilities, ensuring high efficiency and precision.

Professionals with Vast Experience

Our team is made up of highly skilled professionals with years of experience in mold design, prototyping, and production. Whether your project requires a mold of complex size, shape, or design, we have the expertise to deliver exceptional results.

Over 20 Years of Industry Experience

With over two decades of industry experience, we’ve accumulated a wealth of knowledge that allows us to consistently produce high-quality molds. This experience also helps us provide outstanding service to meet your specific needs.

Advanced Mold Flow Analysis Techniques

We utilize advanced mold flow analysis in our design process to ensure we get everything right before moving to production. This method allows us to predict potential issues and optimize the mold for flawless performance.

Custom-Tailored Tooling Solutions

Every mold we produce is custom-made to fit the unique requirements of our customers. From the initial design phase to the final production, we ensure that the mold meets your specifications perfectly.

Cost-Effective Solutions

Our molds offer excellent value for money. While we maintain competitive pricing, we never compromise on the quality and durability of our products.

Swift Delivery

Our well-coordinated logistics team ensures fast and reliable delivery, so you get your molds on time, every time. We are dedicated to maximum customer satisfaction by meeting deadlines and maintaining high standards.

Common Mold Types

Mold Type	Advantages	Disadvantages	Suitable Applications
Die Casting Mold	Relatively low manufacturing cost, high production efficiency, suitable for mass production	Long mold manufacturing cycle, high manufacturing cost, requires high precision machining	Automotive parts, consumer electronics, industrial components
Gravity Casting Mold	Lower mold manufacturing cost, high production efficiency, suitable for large part production	Higher complexity of molds, relatively shorter mold lifespan, longer production cycles	Aerospace components, automotive engine blocks, marine parts
Low Pressure Casting Mold	High surface finish of molded parts, high dimensional accuracy, suitable for producing complex structural components	Higher manufacturing cost, relatively lower production efficiency, limited mold lifespan	Aircraft interiors, architectural elements, high-end consumer products

Additional Notes:

Die casting molds are recommended for high-volume production where cost efficiency and production speed are critical.
Gravity casting molds are ideal for large, non-critical parts with lower production volumes.
Low pressure casting molds are best suited for applications requiring superior surface finish and dimensional accuracy, despite higher manufacturing costs.

Common Mold Design

This table outlines essential elements in mold design, including cavity design, cooling systems, gating systems, and draft angles.

Aspect	Description	Typical Parameters / Considerations	Associated Components / Actions
Cavity Design	Designing the shape and size of the mold cavity to ensure accuracy and quality of the workpiece.	Typical precision range: ±0.01 to ±0.05 mm	Injection pressure, mold temperature control
Cooling System	Designing efficient cooling channels to accelerate workpiece cooling and improve production efficiency.	Cooling time: typically 2-5 seconds per cycle	Water circulation system, cooling channels
Gating System	Designing appropriate gating positions and structures to ensure proper filling of the mold cavity, avoiding gas and inclusion formation.	Gate structures: sprue, runner, gates (e.g., edge gate, pinpoint gate)	Venting system, inclusion traps
Draft Angle	Determining the inclination angle of the workpiece when ejecting from the mold to prevent damage to the workpiece or mold due to friction.	Standard draft angle: typically 1-3 degrees	Ejector pins, ejector plates
CAD Software	Utilizing CAD software for three-dimensional design and modeling of the mold, facilitating precise design iterations and modifications.	N/A	N/A
Simulation Software	Employing simulation software for mold flow analysis, stress analysis, etc., to optimize design solutions and enhance manufacturing precision and efficiency.	N/A	N/A

Common Mold Material

Mold Material	Thermal Conductivity (W/m·K)	Wear Resistance	Coefficient of Thermal Expansion (×10^-6 /°C)	Cost	Lifespan (cycles)	Usage Rate (%)	Actual Applications
Tool Steel	High (20-60)	Good	Moderate (10-20)	Moderate to High	500,000-1,000,000	60	Automotive engine components, consumer electronics housings
Aluminum Alloy	High	Moderate	Moderate (10-20)	Moderate	100,000-500,000	30	Automotive transmission cases, electronic enclosures
Ceramic	Low	High	Low (5-10)	High	100,000-300,000	10	Aerospace turbine blades, medical device components

Note: Ceramic molds are utilized in aerospace for turbine blades due to their exceptional wear resistance and ability to produce intricate designs with fine surface finishes.

Capabilities

Industry