Surface Finishing
Our Surface Finishing Capabilities
PProto Expedited offers professional and high quality surface finishing service for our customers. We have more than 10 experienced experts who only do surface finishing job, therefore, you don’t need to worry the quality.
Choose The Right Finish For Your Material
Different surface finishes can be applied to different materials. You can easily find what you need for your material in the below sheet.
| Name | Material Compatibility |
|---|---|
| Smooth surface (1.6 Ra μm/64 Ra μin) | All plastics and metals |
| Bead blasting | All metals |
| Powder coating | All metals |
| Anodizing clear (type II) | Aluminum alloys |
| Anodizing color (type II) | Aluminum alloys |
| Anodizing hardcoat (type III) | Aluminum alloys |
| Brushing + Electropolishing (0.8 Ra μm/32 Ra μin) | All metals |
| Black oxide | Stainless steel |
| Chromate conversion coating | Aluminum |
| Brushing | All metals |
What you can get from us
Here is a list of standard surface finishes. Please contact danny@protoexpedited.com if the surface finish you need is not one of the below.
As machined
“As machined” is our standard finish for all metal and plastic parts. It has a surface roughness of 3.2 μm (126 μin). All sharp edges are removed and parts are deburred. Machine marks are visible on the surface.
Smooth surface
This can reduce part’s surface roughness and look smoothly. The standard smoothing surface roughness (Ra) is 1.6 μm (64 μin). Machine marks are less evident but still visible on the surface.
Bead blasting
Bead blasting is the operation of propelling, typically with compressed air, a stream of abrasive material (blast media) against a surface to affect the surface finish. Our standard grit is #120 unless otherwise specified.
| Requirement | Specification |
|---|---|
| Grit | #120 |
| Color | Raw material color |
Anodizing color or clear (type II)
Type II anodizing is a process done by placing the aluminum in a sulfuric bath which builds up the aluminum oxide on the surface as well as into the aluminum material too, about half and half. The fact that this process builds into the aluminum material also creates an interesting property of the aluminum oxide making it a great electrical insulator.
| Requirement | Specification |
|---|---|
| Thickness | 8 – 12 μm (clear), 4 – 8 μm (color) |
| Color | Black, clear or any RAL code or Pantone number |
Anodizing hardcoat (type III)
Type III (hardcoat) anodizing is an anodizing process that forms an extremely hard, abrasion resistant, porous oxide on aluminum.
| Requirement | Specification |
|---|---|
| Thickness | 50 – 125 μm |
| Color | Black or clear |
Powder Coating
The powder coated part is then placed into an oven to cure. The polymer resin within the powder begins to adhere with heat on the surface of the part, resulting in a thick coating that is incredibly durable compared to other surface finishes.
| Requirement | Specification |
|---|---|
| Thickness | 18 – 72μm |
| Color | Black or any RAL code or Pantone number. |
Electropolishing
Electropolishing is an electrochemical finishing process that removes a thin layer of material from a metal part, typically stainless steel or similar alloys. The process leaves a shiny, smooth, ultra-clean surface finish.
| Requirement | Specification |
|---|---|
| Color | Natural metal color. |
Black Oxide
Black oxide is the conversion coating formed by a chemical reaction with the iron in metal to form an integral protective surface…contrasted to an applied coating which bonds to the metal but does not react chemically.
| Requirement | Specification |
|---|---|
| Color | Black |
Chromate conversion coating (Alodine/Chemfilm)
Chromate conversion coating for aluminum and other types of metal is a chemical immersion process that is used to passivate and convert the surface properties of the substrate.
| Requirement | Specification |
|---|---|
| Color | Clear |
Brushing
Brushing is a surface treatment process in which abrasive belts are used to draw traces on the surface of a material.
| Requirement | Specification |
|---|---|
| Surface roughness | 0.8 – 1.5 μm |
| Grit | #80-120 |