Shaft
Diameter
Load Bearing
Capacity
Inside Post
Diamter Round
Inside Post
Diamter Square
4x4 Post 6x6 Post
Wood Metal Wood Metal
6" 6,000 lbs 3-1/2" 2-1/2"
8" 10,000 lbs 5" 3-1/2"
10" 14,000 lbs 7" 4-15/16"
12" 18,000 lbs 7-3/4" 5-1/2"
14" 20,000 lbs 9" 6-3/8"
16" 20,000 lbs 10-1/2" 7-7/16"
18" 20,000 lbs 11-3/4" 8-5/16"
20" 20,000 lbs 13-7/8" 10"
22" 20,000 lbs 15-1/4" 11"
24" 20,000 lbs 17" 12-3/16"
30" 30,000 lbs 22-1/2" 15-3/4"
36" 30,000 lbs 25-1/2" 18"