Low Pressure Casting vs Gravity Casting: What’s the Difference?

In the modern foundry industry—especially in brass sanitary hardware, automotive parts, and precision metal components—casting technology plays a decisive role in product quality and production efficiency. Among all casting methods, Low Pressure Casting and Gravity Casting are the two most widely used processes.

Although both methods shape molten metal inside a metal mold, they differ significantly in metal flow behavior, process control, casting quality, and applicable products. This article provides a clear and professional comparison to help manufacturers choose the most suitable casting process for their production needs.

1.What Is Low Pressure Casting?

Low Pressure Casting is a process where molten metal is pushed upward into a mold cavity under controlled low pressure (usually 0.05–0.15 MPa).

Instead of free-falling into the mold, the metal is filled in a smooth, stable, and non-turbulent manner.

✔ Key Features of Low Pressure Casting

·Stable metal filling reduces turbulence and oxidation.

·Higher casting density with fewer pores or shrinkage.

·Precise process control for complex or thin-wall geometries.

·High casting quality suitable for demanding industries.

✔ Common Applications

·Brass faucets and valve bodies

·Automotive wheels and structural components

·High-precision mechanical parts

·Complex or thin-wall castings

Low Pressure Casting is widely used where tight tolerances and defect-free surface quality are required.

2.What Is Gravity Casting?

Gravity Casting (also known as gravity die casting) is a process where molten metal flows into the metal mold solely under its own weight, without external pressure.

✔ Key Features of Gravity Casting

·Simple process and lower equipment cost

·Suitable for thick-wall or simpler geometries

·Good mechanical strength, especially for larger parts

·Fast production cycle and easy mold maintenance

✔ Common Applications

·Sanitary hardware

·Automotive components

·Industrial metal parts

·Thick-wall or medium-complexity castings

Gravity casting remains a cost-effective and stable production method for many foundries.

3.Low Pressure Casting VS Gravity Casting:Side-by-Side Comparison

4.Which Casting Method Should You Choose?

Choose Low Pressure Casting if you need:

·High-precision brass components

·Thin-wall or complex geometries

·Defect-free surfaces

·Strong mechanical performance

·High stability and repeatability

Choose Gravity Casting if you want:

·Lower equipment investment

·Lower cost per part

·Thick-wall or medium-precision castings

·Simpler tooling

·Fast production with stable output

5.Why Many Brass Manufacturers Are Moving Toward Low Pressure Casting?

In the sanitary ware and hardware industry (faucets, valves, bathroom accessories), many manufacturers have already upgraded to low pressure casting due to its superior:

·surface quality

·internal density

·product consistency

·casting precision

As customer quality expectations increase, low pressure casting has become the preferred solution for premium brass products.

6.DingZhu Intelligent Equipment – Professional Manufacturer of Casting Machines

Xiamen DingZhu Intelligent Equipment specializes in brass casting machinery, including:

·Low Pressure Die Casting Machines

·Gravity Die Casting Machines

·Automatic Sand Core Shooting Machines

·Robotic Polishing & Grinding Cells

·Complete Foundry Automation Solutions

We help customers achieve:

·Higher casting quality

·Lower defect rate

·Improved productivity

·Safer and more efficient manufacturing environments

For complete casting solutions, technical support, and customized production line design, contact our

engineering team anytime.