For Helix Plates Welded to 1-1/2” Square Shafts:
Helix Thickness
3/8”
1/2”
3/8”
1/2”
3/8”
1/2”
3/8”
1/2”
Helix Diameter
8”
8”
10”
10”
12”
12”
14”
14”
Minimum (Ultimate)
Compressive Load
35,000 lbs
55,000 lbs
20,000 lbs
50,000 lbs
20,000 lbs
49,800 lbs
20,000 lbs
42,250 lbs
For Helix Plates Welded to 1-3/4” Square Shafts:
Helix Thickness
3/8”
1/2”
3/8”
1/2”
3/8”
1/2”
3/8”
1/2”
Helix Diameter
8”
8”
10”
10”
12”
12”
14”
14”
Minimum (Ultimate)
Compressive Load
35,000 lbs
70,000 lbs
30,000 lbs
65,000 lbs
27,500 lbs
55,000 lbs
22,500 lbs
50,000 lbs

The above summary is the lowest test result of three sample tests for each product.
Test results are mechanical and do not include a safety factor or consideration of
variations in soil conditions. Testing was conducted by an independent laboratory
and full details are available upon request.