MIM Tolerence

Injection molding tolerances range between 0.3% and 0.5%, although tighter tolerances can be achieved if deemed necessary. Since MIM components range in size over a wide range of sizes, it can be difficult to address tolerances directly. Occasionally, the tolerance versus size table has been created, showing capabilities as follows: MIM tolerances can be obtained in a single batch, but are usually subject to wider variation over time.
The Size RangeSuggestion Tolerance
<1.02mm±0.025
up to 3.05mm±0.025
up to 6.1mm±0.051
up to 11.94mm±0.051
up to 24.89mm±0.102mm
  • Weight Range: less than 200g
  • Right Weight:0.1g-50g
  • Wall thickness:0.15-5mm

Material:

MIM DESIGN

In general,we could follow the thermoplastic injection design standards.Many factors,such as material, location, etc., could affect the tolerance. In General, the MIM tolerance range is at ±0.5%.

  • Avoid the sharp edge,  recommended radius is 0.2mm
  • The draft angle is at 0.5-2 degree
  • Keep the same thickness
  • Flat surface
mim parts

Item

Tolerence ±

Qualified ±

Absoluted Dimension

0.025 mm (0.001 inch)

0.05 mm (0.002 inch)

Angle

0.05°

Density

0.2%

1%

Dimension

0.05%

0.3%

Flatness

0.1%

0.2%

Hole Diameter

0.04%

0.1%

Hole Location

0.1%

0.3%

Parallelism

0.2%

0.3%

Perpendicularity

0.1% or 0.1°

0.2% or 0.3°

Roundness

0.3%

0.3%

Surface Roughness

0.2 µm (8 µ inch)

0.8 µm (32 µ inch)

Weight

0.1%

0.4%

Radius

0.1 mm (0.004 inch)

0.15 mm (0.006 inch)

Got a Question?

FAQ

The tolerance for injection molded parts typically depends on various factors such as the material being used, the part geometry, and the capabilities of the molding equipment. In general, injection molding can achieve tight tolerances, often in the range of +/- 0.005 to 0.010 inches (+/- 0.127 to 0.254 millimeters). However, it’s important to note that achieving tight tolerances may come with increased cost and complexity.

Factors that can affect the tolerance include:

1. Material: Different materials have different shrinkage rates during cooling, affecting the final dimensions of the part. Some materials, like ABS or polystyrene, have relatively low shrinkage rates, while others, like nylon or polypropylene, have higher rates.

2. Part geometry: Complex, intricate, or thin-walled designs may require tighter tolerances due to potential warping, sink marks, or other molding challenges. Simple, uniform shapes generally have less variation.

3. Molding process: Factors like mold temperature, injection pressure, cooling time, and flow rate can influence the dimensional accuracy of the part. Fine-tuning these parameters is crucial to achieving the desired tolerances.

4. Mold design and maintenance: The precision and quality of the injection mold play a significant role in determining the achievable tolerances. Proper design, fabrication, and frequent maintenance help ensure consistent results.

It is always recommended to consult with an experienced injection molding engineer or manufacturer to determine the specific tolerance requirements for your particular project. They can provide guidance based on your design, material choice, and production capabilities.

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