ASTM-B-488
Standard Specification for Electrodeposited Coatings of Gold
This specification establishes the requirements for electrodeposited gold coatings.Coatings are classified into types based on minimum purity characteristics and codes which provide Knoop hardness.
Purity
| ASTM Type | Purity, Code, and Finish |
| Type I | 99.7% pure Au with a hardness from A (90 HK25 max) to C (130-200 HK25) |
| Type II | 99.0% pure Au (hard Au) with hardness from B (91-129 KH25) to D (>200 HK25) |
| Type III | 99.9% pure Au is soft gold with a hardness of A only (90 HK25 Max) |
Hardness
| ASTM Code | Knoop Hardness |
| Code A | 90 HK25 max |
| Code B | 91-129 KH25 |
| Code C | 130-200 HK25 |
| Code D | over 200 HK25 |
Purity (Type) and Hardness (Grade) Relationship
| ASTM Type | Code |
| Type I | Code A, B, and C |
| Type II | Code B, C, and D |
| Type III | Code A Only |
Thickness
| Class | Minimum Thickness [um] |
| 0.25 | 0.25 |
| 0.50 | 0.50 |
| 0.75 | 0.75 |
| 1.0 | 1.0 |
| 1.25 | 1.25 |
| 2.5 | 2.5 |
| 5.0 | 5.0 |
Recommended Drawing Call-Outs:
- Plate electrodeposited Nickel / Gold per ASTM-B-488
- Thickness requirements per IPC-6012 or IPC-6013 (respectively), or follow table below:
