Aluminum Anodizing
Hard and soft anodic coatings that improve wear and corrosion resistance.
Aluminum Anodizing
EF Technology specializes in hard and soft sulfuric acid anodizing of aluminum alloy parts. Parts that need wear resistance receive hard coatings; parts where corrosion resistance and appearance matter receive soft coatings.
Hard
Soft
Hard or Soft: Which to Choose
01Hard Anodizing
WhatA thick, hard coating (15–40 µm, HV 400 or higher) that withstands wear.
WhyParts with reciprocating or sliding friction, such as brake pistons and valves, need a coating that does not wear away.
HowThickness and hardness are controlled separately to the thickness, hardness and corrosion requirements on the drawing (MS633-06, TS2-25-102, MIL-PRF-8625 Type III, etc.).
ResultThe color is in the dark gray-brown range, and sealing is applied only when specified on the drawing.
02Soft Anodizing
WhatA thin, even coating (5–30 µm) that provides corrosion resistance and appearance.
WhyIt suits parts where the dimensional stability of assembly and sealing surfaces and a clean surface matter, such as hydrogen tank, HVAC and motor components.
HowThickness is controlled to MIL-PRF-8625 Type II or customer grade criteria, and the coating is finished with sealing.
ResultThe natural color is silver for wrought alloys and gray for die-cast alloys; black dyeing is also available.
03Selection Criteria
WhatIf the drawing specifies a standard, that standard takes priority.
WhyEven for the same part, thickness measurement locations, hardness test methods and salt spray duration differ by customer standard.
HowWithout a specified standard, the choice is made by asking "Is there friction? (hard) / Are dimensions and appearance critical? (soft)", and EF Technology also advises on color and thickness limits by material (6061, 7075, ADC12).
ResultEF Technology reviews submitted drawings and replies with the option that fits.
Specifications
Item | Specification |
|---|---|
| Materials | 6061-T6, 7075-T6 and other aluminum alloys |
| Process | Hard and soft sulfuric acid anodizing |
| Coating thickness | Hard 15–40 µm · soft 5–30 µm (controlled to drawing values) |
| Color | Undyed natural color — silver to dark gray-brown depending on alloy and coating thickness |
| Maximum part size | Length 3,000 × width 500 × depth 950 mm (internal tank dimensions; subject to rack configuration) |
Send us a drawing or photo and we will review whether we can process the part.Request a Quote