Class |
Circumference at Top |
Circumference at 6 Feet from Butt |
Strength |
Common Uses |
Typical Length |
Class 1 |
42 inches |
27.5 inches |
Highest load-bearing capacity |
High-voltage power lines, critical infrastructure |
40 to 90 feet |
Class 2 |
37.5 inches |
25.5 inches |
Very high load-bearing capacity |
Major distribution lines, street lighting |
35 to 90 feet |
Class 3 |
33 inches |
23.5 inches |
High load-bearing capacity |
General distribution lines, medium-duty applications |
30 to 80 feet |
Class 4 |
28.5 inches |
21.5 inches |
Good load-bearing capacity |
Standard utility poles, telecommunications |
25 to 75 feet |
Class 5 |
24 inches |
19.5 inches |
Moderate load-bearing capacity |
Light-duty distribution lines, secondary power lines |
25 to 65 feet |
Class 6 |
19.5 inches |
17.5 inches |
Lower load-bearing capacity |
Service poles, light-duty applications |
20 to 60 feet |
Class 7 |
15 inches |
15.5 inches |
Lowest load-bearing capacity |
Minimal structural requirements, temporary structures |
20 to 55 feet |