Full Service Custom Injection Molding Supplier in China

Save Money With an Injection Molding Company That Helps You Design For Manufacturing.

injection Mold Manufacturer in China

Looking for reliable molds for your next injection molding project? Stebro Mold specializes in designing and manufacturing high-quality production molds, prototype molds, unscrewing molds, collapsible core molds, molds requiring multiple slides and lifters, 2K molds, insert molds, and over molds for OEMs and plastic injection molding companies.

The entire development process from the initial design meeting to the delivery of your finished mold relies on meticulous engineering and planning. We do not just take a customer’s product drawing or 3D part design verbatim and build a mold. Our responsibility is to take ownership of that mold, so we have to critique it, go through our customer’s requirements, and obviously make suggestions if we see potential issues or if we can make enhancements.
We do a lot of parts sampling, troubleshooting and mold validation. When we build new molds, we want to ensure that they go to our customer’s facilities without any issues for a smooth transition to production. Validation services can include PPAP, first article inspection, design of experiments, IQ/OQ/PQ process validations, factory acceptance tests, and more. 
Contact us for your next plastic injection mold project. Our promise to you is optimized cycles, quality parts, and low maintenance!!!

Injection Mold Making

Two Shot Mold
Insert Mold
Over Mold
Gas Injection Mold
Unscrewing Mold
Prototype Mold
Hot Runner Mold
MUD Insert Mold
Mass Production Mold

Why Stebro Mold for Plastic injection mold making

on-time delivery, world-class craftsmanship and a fair price

Customer Letters

Amanda Lee
CEO & Founder Crix
Catherine Gilbert
Director at Initech
One-stop solution for Plastic Part from part design to final Delivery

Basic Injection Mold Knowleage

What is Injection Mold?

An injection mold is a tool used in manufacturing to create plastic parts by injecting molten plastic into a mold cavity under high pressure. Once the plastic cools and solidifies, the mold is opened, and the finished part is ejected.

Injection Mold Manufacturing processes step by step

  1. Product development and optimize
  2. Prototype to check the part
  3. Mold Design
  4. Moldflow to optimize the mold design
  5. Order the steel, Moldbase, and mold component
  6. Gun drilling for the cooling line
  7. CNC rough manufacturing on the cavity and core inserts, slides, and lifters
  8. Heat Treatment
  9. CNC fine manufacturing the cavity and core inserts, slides, and lifters 
  10. EDM manufacturing
  11. Wire Cut manufacturing
  12. Fitting the mold
  13. Polish
  14. Assemble the mold
  15. Mold test
  16. Sample checking
  17. Mold improvement

Injection Mold Advantages

  • Automation and high production rate
  • Material and color Versatility
  • Plastic material can be recycled, and minimal waste
  • Consistent quality and high tolerance precision
  • Flexibility design, Parts can be complex shapes

Injection Mold Disdvantages

  • Initial tooling cost is high
  • Limited flexibility after the mold is done
  • Long lead time

Injection Mold Design key consideration

  • Uniform wall thickness 
  • Draft angle optimization
  • Cavity number based on part volume
  • Steel material selection based on the plastic material, surface requirement, and part volume
  • Gate system
  • Efficient cooling design
  • Venting and ejection system
  • Easy Mold Maintenance

injection Mold steel

SteelHardnessPropertiesPlastic Material ApplicationsSurface Finish
H13HRC48-52Excellent toughness, wear resistance, and thermal conductivity. Maintains hardness at high temperatures.PC, PMMA, PP, PE, PA+GFSPI A1, A2, B1, B2
S136HRC48-52Excellent corrosion resistance and dimensional stability. Good toughness, wear resistance, and polishability.PC, PMMA, POMSPI A1, A2, B1, B2
NAK80HRC38-42Excellent dimensional stability, wear resistance, and mirror polishability.PCSPI A1, A2
P20HRC28-32Good wear resistance, toughness, and machinability. Can be heat-treated for higher hardness.ABS, PE, PPSPI A1, A2, B1, B2
P20HHRC32-37Similar to P20, but with higher hardness and improved wear resistance.ABS, PE, PP, PETSPI A1, A2, B1, B2

Injection mold Manfaucturing Tolerance

The manufacturing tolerance for injection molds can vary depending on a number of factors, such as the complexity of the mold design and the materials used. However, in general, the tolerance for injection molds is typically within +/- 0.005 inches or +/- 0.01 mm.

It’s important to note that some features of the mold may require tighter tolerances, particularly if they are critical to the function of the final product.

In addition to manufacturing tolerances, it’s also important to consider the tolerance of the final product. This refers to the allowable deviation in the dimensions and features of the plastic parts produced from the mold. Understanding and controlling both the mold manufacturing tolerance and the part tolerance is crucial in ensuring high-quality injection molded parts.

Injection Mold Surface finish

PolishedTexturedMachining SurfaceSecondary Finishes
High Gloss PolishMold Tech MT-XXXXEDM SurfacePainting
Technical PolishVDI VDI3400CHXXMilling SurfaceChrome Plating

SPI Mold Surface Finishes

SPI FinishManufacturing MethodSurface Roughness RaTypical Application
A1Grade #3 Diamond0.012-0.025Mirror Polish
A2Grade #6 Diamond0.025-0.05High Gloss Polish
A3Grade #15 Diamond0.05-0.1High Gloss Polish
B1600 Grit Paper0.05-0.1Fine Semi Glossy Finish
B2400 Grit Paper0.1-0.15Medium Semi Glossy Finish
B3320 Grit Paper0.28-0.32Normal Semi Glossy Finish
C1600 Grit Stone0.35-0.4Fine Matte Finish
C2400 Grit Stone0.45-0.55Medium Matte Finish
C3320 Grit Stone0.63-0.70Normal Matt Finish
D1 #11 Glass Bead0.8-1.0Satin Textured Finish
D2#240 Aluminum Oxide Blast1.0-2.8Dry Textured Finish
D3#24 Aluminum Oxide Blast3.2-18Rough Texture Surface

Plastic Injection Molds Cost

Tooling cost = Mold design cost + Steel material cost + mold base cost + mold components cost + Manufacturing cost + Mold Trial + Delivery cost

Injection mold application industry

Plastic Injection Mold Making Equipment

The process of making plastic injection molds requires specialized equipment and machinery to produce molds that meet the required specifications. Some of the key equipment used in plastic injection mold making include:

  • Gun Drilling Machine
  • CNC Machine
  • EDM Machine
  • Wire Cut Machine
  • Lathe Machine
  • Grinding Machine
  • Mold fitting Machine

Plastic injection mold Resources

injection molding surface finish

Table of Contents Surface finishes play a crucial role in the plastic injection molding process, impacting the appearance, functionality, and overall quality of the final

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