Die Fillet

2024-08-28 by Cherry 

Mold design is the core of the manufacturing industry,

and die fillet, as an important part of it, plays 

an indispensable role.

This article will explore the definition, function,

design principles and application of die fillet 

in die casting machines. 

Through a detailed explanation of this concept and

practical suggestions, it helps readers better understand

and apply to die fillet, thereby improving product quality

and production efficiency.

What is Die Fillet? ‌

‌

Die fillet refers to the smooth transition area at the

corner of the inner or outer contour of the mold.

Simply put, it is a circular connection part that 

transitions from one plane or curved surface to another 

plane or curved surface. The existence of die fillet

helps to reduce stress concentration and prevent cracks

or breakage of materials due to excessive stress during 

processing or use.

The role of die fillet

Die fillet can improve the durability of the mold, ensure 

the accuracy of the product, and simplify the manufacturing

process of the mold. ‌

Reasonable fillet design can reduce the stress concentration

of the mold during the stamping process,

reduce the risk of mold damage, and make the gap of the mold

more uniform, improving the precision of the product.

Die fillet plays a vital role in mold design and manufacturing. 

The following are several key functions of die fillet:



1. Reduce stress concentration: At the corners of the mold,

if there is no fillet, the material

will produce stress concentration when it is stressed. 

This stress concentration is prone to fatigue failure of the

material and proper fillet design can effectively disperse 

stress, reduce the stress concentration of the mold during

the stamping process, reduce the risk of mold damage, and 

make the gap of the mold more uniform, improve the precision 

of the product, and extend the service life of the mold.



Improve material fluidity: During the die-casting process, 

liquid metal needs to fill the mold quickly. 

The design of the die fillet can improve the fluidity of the

material, allowing the liquid metal to flow more smoothly

and avoid problems such as incomplete filling or bubbles.



Enhance mold strength: Mold fillet can effectively reduce 

the fragility of mold edges and increase the overall mechanical

strength of the mold, especially when subjected to high-pressure

in the die-casting machine. 

Die fillet can improve the durability of the mold, ensure the

accuracy of the product, and simplify the manufacturing process

of the mold.



Improve surface quality: Smooth transition not only helps to 

improve the durability of the mold, but also improve the surface

quality of the final product, making the product's appearance

smoother and more beautiful.



Design principles of die fillet

The design of die fillets is a process that requires a comprehensive

consideration of multiple factors.

The following are some basic principles that should be followed

when designing die fillets:



1. Choice of fillet size: The radius of the fillet should be

determined according to the material, process requirements,

and use conditions of the mold.

Generally speaking, the larger the fillet radius,

the more conducive it is to reducing stress concentration,

but too large a fillet may also affect the accuracy and 

function of the mold. Therefore, a reasonable fillet size is crucial.



2. Uniform transition: The fillet should be consistent with

other geometric features of the mold to ensure a uniform

and smooth transition.

This not only helps to improve material fluidity but also 

avoids unnecessary defects in the production process.



3. Consider the mold processing method: When designing the mold radius,

the mold processing method should also be considered. 

Different processing processes have different requirements 

for radius. For example, casting, forging, or cutting processing

may have different restrictions on radius design.



Avoid sharp corners and acute corners: In-mold design, sharp

corners and acute corners should be avoided as much as possible,

because these parts are prone to stress concentration and cracks,

reducing the service life of the mold.



4. The relationship between mold radius and die-casting machine

In the application of die-casting machine, the design of the mold 

radius is particularly important. 

Die-casting is a molding method that injects liquid metal

into the mold under high pressure.

This process requires the mold to have extremely high precision 

and durability. The mold radius plays the following key 

roles in this process:



1. Optimize material flow: During the die-casting process, 

liquid metal fills the mold at a very fast speed.

Reasonable design of mold radius can avoid eddy currents

or dead corners during material flow, thereby ensuring

that all parts of the mold can be evenly filled and 

reduce defects in castings.



2. Improve product quality: Mold radius helps reduce stress

concentration inside the casting, thereby reducing

the incidence of product deformation, cracks, and

other defects.

This is essential to ensure the high quality of die-cast products.



3. Extend mold life: Since the die-casting machine generates

extremely high pressure when working, the durability

of the mold becomes a key issue.

Mold radius can reduce stress concentration, reduce mold

wear and fatigue under high pressure, and extend the

service life of the mold.



Challenges in design and manufacturing

Although mold radius design sounds simple in theory, it 

faces many challenges in the actual design and manufacturing

process. 

The design of the mold radius needs to be weighed and decided

according to the specific situation. For example, when designing

thick-walled products, maintaining the consistency of mold

radius helps to achieve a uniform distribution of wall thickness.

However, too many mold radiuses will increase the complexity

and cost of mold processing. :



1. Precision control: The design of the mold radius requires 

extremely high precision and a slight deviation may affect

the overall function of the mold and product quality.



2. Material limitations: Different materials have different 

characteristics. When designing mold fillets, it is necessary

to fully consider the machinability and durability of the material.



3. Process complexity: The processing of mold fillets usually

requires complex processes,

such as CNC processing, electrical discharge processing, etc.,

which increases the difficulty and cost of manufacturing.



Multi-process collaboration: The design and manufacturing of die

fillets require the coordination of multiple processes.

From design, and simulation to actual processing, each step is

crucial.



Actual case analysis

In order to better understand the role of mold fillets, we can

analyze an actual die-casting mold design case.

In this case, an automotive parts manufacturer needs to design

a complex die-casting mold for the production of high-precision

engine parts.

In the initial design, due to the failure to fully consider

the role of die fillets, the mold frequently cracked and worn

during use, and the product qualification rate was also low. 

After the redesign, engineers optimized the fillet of the mold, 

increased the fillet radius at key corners, and adopted a more

suitable processing technology.

In the end, the service life of the mold was greatly extended

and the product quality was significantly improved.

Future Development Trends

With the continuous advancement of manufacturing technology,

the design and application of die fillets are also developing.

In the future, with the popularization of intelligent manufacturing

and digital design, the design of mold fillets will be more accurate

and intelligent. 

Through advanced simulation software and optimization algorithms,

engineers can predict and solve potential problems in the design

stage, thereby further improving the performance of the mold

and product quality.

In addition, with the continuous emergence of new materials,

the design of die fillets will face more challenges and

opportunities. 

Future mold design will pay more attention

to the sustainability and environmental friendliness of materials,

and fillet design will also be more in line with the requirements

of green manufacturing.

Conclusion

Die fillets are an indispensable part of mold design.

Its reasonable design can not only improve product quality 

but also extend mold life and reduce production costs. 

In the application of die-casting machines, the role of die fillets

is particularly important. By deeply understanding the principles

and design principles of die fillets, we can better cope with

various challenges in manufacturing and promoting the sustainable

development of the manufacturing industry.

In short, whether in the application of die-casting machines or

other mold design fields, the design of diefillets requires

a high degree of professional knowledge and practical experience.

Hopefully, this article will help readers better understand 

this key concept and apply it in their actual work, leading

to a more efficient and higher-quality manufacturing process.

For more info, you can refer to: 

https://www.tiktok.com/@lk_diecastingmachine/video/7405113006880820522 

https://www.youtube.com/shorts/JLX410QV_kw

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