ASTM A123
ASTM A123 Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products covers the requirements for galvanizing by the hot-dip process on iron and steel products made from rolled, pressed, and forged shapes, castings, plates, bars, and strips. It covers both un-fabricated products and fabricated products, for example, assembled steel products, structural steel fabrications, large tubes already bent or welded before galvanizing, and wire work fabricated from uncoated steel wire. This specification also covers steel forgings and iron castings incorporated into pieces fabricated before galvanizing or which are too large to be centrifuged (or otherwise handled to remove excess galvanizing bath metal). ASTM A123 does not apply to wire, pipe, tube, or steel sheet which is galvanized on specialized or continuous lines. The specification includes minimum coating thicknesses according to material category as well as finish and adherence requirements.
1.ASTM A123 steel types and coating thickness grades
| Material type (In/mm) |
＜1/16(1.6) |
＜1/16～1/8(3.2) |
1/8～3/16(4.8) |
＜3/16～1/4(6.4) |
＞1/4(6.4) |
| Structural member |
45 |
65 |
75 |
85 |
100 |
| Steel plate |
45 |
65 |
75 |
85 |
100 |
| Steel Pipe |
45 |
45 |
75 |
75 |
75 |
| Steel wire |
35 |
50 |
60 |
65 |
80 |
2. ASTM A123 steel layer thickness grade correspondence table
| Thickness grade |
Mils |
Oz/frt2 |
μm |
g/m2 |
|
35 |
1.4 |
0.8 |
35 |
245 |
|
45 |
1.8 |
1.0 |
45 |
320 |
|
50 |
2.0 |
1.2 |
50 |
355 |
|
55 |
2.2 |
1.3 |
55 |
390 |
|
60 |
2.4 |
1.4 |
60 |
425 |
|
65 |
2.6 |
1.5 |
65 |
460 |
|
75 |
3.0 |
1.7 |
75 |
530 |
|
80 |
3.1 |
1.9 |
80 |
565 |
|
85 |
3.3 |
2.0 |
85 |
600 |
|
100 |
3.9 |
2.3 |
100 |
705 |
