Surface Finishing Service
Your one-stop shop for manufacturing and surface finishing. Get your metal and plastic parts CNC machined and bead blasted, anodized, or powder coated in as fast as 5 days.
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Injection Mold Surface Finishing Standerds
Zhongde has access to a diverse marketplace of molding suppliers and all standard mold surface finishing options. Mold finishes can range from glossy to matte to even patterned. Finishes applied to the surface of the mold cavity transfer to the surface of the molded part. For example, a mold surface that is polished to be reflective will make a reflective (or transparent) part. Mold finishes differ from CNC machined or 3D printed parts, where each component is treated individually. Adding a finish or texture can change the tool’s price depending on the process required, but it does not alter the price of the individual parts.
Our standard mold finishes include the following:
- Society of Plastics Industry (SPI) Mold Finishes
- VDI
SPI Finishes vs VDI Finishes
SPI Finishes
SPI Finish (SPI Finishes) is also known as “SPI Mold Finish (SPI Mold Finishes)” or “SPI Surface Finishes“.
The SPI Finish refers to the American surface finish standard set by SPI (Society of the Plastics Industry).
SPI A-1
Diamond buffed with grade #3, 6000 grit for a highly polished finish. Also suitable for producing optically clear parts. Has an average surface roughness of 0.012-0.025µm Ra.
SPI A-2
Diamond buffed with grade #6, 3000 grit for a high polish finish. Also suitable for producing transparent parts. Has an average surface roughness of 0.025-0.050µm Ra.
SPI A-3
Diamond buffed with grade #15, 1200 grit for a high-to-medium polished finish. Also suitable for producing non-optical transparent parts. Has an average surface roughness of 0.050-0.100µm Ra.
SPI B-1
A 600-grit sanded finish for a medium polish with a surface roughness of 0.05-0.10µm Ra.
SPI B-2
A 400-grit sanded finish for a medium polish with a surface roughness of 0.10-0.15µm Ra.
SPI B-3
A 320-grit sanded finish for a medium-to-low polish with a surface roughness of 0.28-0.32µm Ra.
SPI C-1
A 600 stone finish for a low polish with a surface roughness of 0.35-.40µm Ra.
SPI C-2
A 400 stone finish for a low polish with a surface roughness of 0.45-.55µm Ra.
SPI C-3
A 320 stone finish for a low polish with a surface roughness of 0.63-.70µm Ra.
SPI D-1
Dry blasted with glass bead for a satin finish with a surface roughness of 0.80-1.00µm Ra.
SPI D-2
Dry blasted with #240 oxide for a dull finish with a surface roughness of 1.00-2.80µm Ra.
SPI D-3
Dry blasted with #24 oxide for a dull finish with a surface roughness of 3.20-18.00µm Ra.
VDI Finishes
VDI 3400 Surface Finish (known as VDI surface finish) refers to the mold texture standard Verein Deutscher Ingenieure (VDI), the Society of German Engineers. The VDI 3400 surface finish is mainly processed by Electrical Discharge Machining (EDM) when mold machining. VDI is an international standard for mold texturing of matte surfaces. The EDM surface gives a fine-to-coarse grain depending on the selection.
VDI 12
A 600 stone low-polish finish with an average surface roughness of 0.40µm Ra.
VDI 15
A 400 stone low-polish finish with an average surface roughness of 0.56µm Ra.
VDI 18
A glass bead blast satin finish with an average surface roughness of 0.80µm Ra.
VDI 21
A #240 oxide dry blast dull finish with an average surface roughness of 1.12µm Ra.
VDI 24
A #240 oxide dry blast dull finish with an average surface roughness of 1.60µm Ra.
VDI 27
A #240 oxide dry blast dull finish with an average surface roughness of 2.24µm Ra.
VDI 30
A #24 oxide dry blast dull finish with an average surface roughness of 3.15µm Ra.
VDI 33
A #24 oxide dry blast dull finish with an average surface roughness of 4.50µm Ra.
VDI 36
A #24 oxide dry blast dull finish with an average surface roughness of 6.30µm Ra.
VDI 39
A #24 oxide dry blast dull finish with an average surface roughness of 9.00µm Ra.
VDI 42
A #24 oxide dry blast dull finish with an average surface roughness of 12.50µm Ra.
VDI 45
A #24 oxide dry blast dull finish with an average surface roughness of 18.00µm Ra.
SPI Finishes
SPI A-1
Diamond buffed with grade #3, 6000 grit for a highly polished finish. Also suitable for producing optically clear parts. Has an average surface roughness of 0.012-0.025µm Ra.
SPI A-2
Diamond buffed with grade #6, 3000 grit for a high polish finish. Also suitable for producing transparent parts. Has an average surface roughness of 0.025-0.050µm Ra.
SPI A-3
Diamond buffed with grade #15, 1200 grit for a high-to-medium polished finish. Also suitable for producing non-optical transparent parts. Has an average surface roughness of 0.050-0.100µm Ra.
SPI B-1
A 600-grit sanded finish for a medium polish with a surface roughness of 0.05-0.10µm Ra.
SPI B-2
A 400-grit sanded finish for a medium polish with a surface roughness of 0.10-0.15µm Ra.
SPI B-3
A 320-grit sanded finish for a medium-to-low polish with a surface roughness of 0.28-0.32µm Ra.
SPI C-1
A 600 stone finish for a low polish with a surface roughness of 0.35-.40µm Ra.
SPI C-2
A 400 stone finish for a low polish with a surface roughness of 0.45-.55µm Ra.
SPI C-3
A 320 stone finish for a low polish with a surface roughness of 0.63-.70µm Ra.
SPI D-1
Dry blasted with glass bead for a satin finish with a surface roughness of 0.80-1.00µm Ra.
SPI D-2
Dry blasted with #240 oxide for a dull finish with a surface roughness of 1.00-2.80µm Ra.
SPI D-3
Dry blasted with #24 oxide for a dull finish with a surface roughness of 3.20-18.00µm Ra.
VDI Finishes
VDI 3400 Surface Finish (known as VDI surface finish) refers to the mold texture standard Verein Deutscher Ingenieure (VDI), the Society of German Engineers. The VDI 3400 surface finish is mainly processed by Electrical Discharge Machining (EDM) when mold machining. VDI is an international standard for mold texturing of matte surfaces. The EDM surface gives a fine-to-coarse grain depending on the selection.
VDI 12
A 600 stone low-polish finish with an average surface roughness of 0.40µm Ra.
VDI 15
A 400 stone low-polish finish with an average surface roughness of 0.56µm Ra.
VDI 18
A glass bead blast satin finish with an average surface roughness of 0.80µm Ra.
VDI 21
A #240 oxide dry blast dull finish with an average surface roughness of 1.12µm Ra.
VDI 24
A #240 oxide dry blast dull finish with an average surface roughness of 1.60µm Ra.
VDI 27
A #240 oxide dry blast dull finish with an average surface roughness of 2.24µm Ra.
VDI 30
A #24 oxide dry blast dull finish with an average surface roughness of 3.15µm Ra.
VDI 33
A #24 oxide dry blast dull finish with an average surface roughness of 4.50µm Ra.
VDI 36
A #24 oxide dry blast dull finish with an average surface roughness of 6.30µm Ra.
VDI 39
A #24 oxide dry blast dull finish with an average surface roughness of 9.00µm Ra.
VDI 42
A #24 oxide dry blast dull finish with an average surface roughness of 12.50µm Ra.
VDI 45
A #24 oxide dry blast dull finish with an average surface roughness of 18.00µm Ra.
Exploring the World of Mold Surface Texture
Injection molding surface texture refers to the specific characteristics and qualities of the mold surface that are intentionally designed to influence the appearance, feel, and functionality of the molded plastic parts.
Secondary Surface Finishing
Here is a list of optional super surface finishes. For custom high metal surface finishes such as electroplating or polishing, please contact sales@zdcpu.com.
As Machined
For as machined all sharp edges are removed and parts are deburred. Tool marks are visible.
Smoothing
A finishing CNC machining operation can be applied to the part to reduce its surface roughness. Machine marks are less evident but still visible.
Material compatibility: All plastics and metals
Bead Blasting
Bead blasting adds a uniform matte or satin surface finish on a machined part, removing the tool marks. This is used mainly for visual purposes and comes in several different grits which indicate the size of the bombarding pellets.
Material compatibility: All metals
Color: Uniform matte of raw material color
Powder Coating
Powder coating is a strong, wear-resistant finish that is compatible with all metal materials and can be combined with a bead blasting to create parts with smooth and uniform surfaces and excellent corrosion resistance.
Material compatibility: All metals
Color: Black or any RAL code or Pantone number.
Anodizing Color (Type II)
Type II anodizing is mainly used to produce parts with a uniform, aesthetically pleasing surface and provides good corrosion and limited wear resistance.
Material compatibility: Aluminum alloys
Color: Black, clear or any RAL code or Pantone number
Anodizing Hardcoat (Type III)
Type III anodizing provides excellent corrosion and wear resistance, suitable for functional applications.
Material compatibility: Aluminum alloys
Color: Black or clear
Electropolishing
Electropolishing is an electrochemical process used to polish, passivate and deburr metal parts. It is useful to reduce surface roughness.
Material compatibility: All metals
Color: Natural metal color
Black Oxide
Black oxide is a conversion coating used to improve corrosion resistance and minimize light reflection.
Material compatibility: Stainless steel and copper alloys
Color: Black
Chromate Conversion Coating (Alodine/Chemfilm)
Chromate conversion coating is used to increase the corrosion resistance of metal alloys while maintaining their conductive properties.
Material compatibility: Aluminum and copper alloys
Color: Clear or yellow
Brushing
Brushing is produced by polishing the metal with grit resulting in a unidirectional satin finish. Not advisable for applications where corrosion resistance is required.
Material compatibility: All metals
Knowledge Hubs
Understanding Hot Runner and Cold Runner Systems In Injection Molding
Runner systems are the vital pathways that direct molten material into molds, a fundamental component of the injection molding process. In this post, we explore
An Injection Mold Polishing Guide for Enhance Injection Molded Parts Quality and Performance
Injection mold polishing plays a crucial role in the manufacturing process of plastic components. It is a technique used to enhance the surface finish and
Exploring 2-Shot Injection Molding: Process, Advantages, and Considerations
In the ever-evolving landscape of manufacturing, innovation is the key to staying ahead of the curve. 2-shot injection molding( two-shot injection molding) also named double