Steel Base Plates with 3/8" holes:

3" x 3" x 3/16"        4" x 4" x 3/16"

4" x 4 " x 3/8"        5" x 5" x 1/4"

6" x 6" x  1/4"         6" x 6" x 3/8"

8" x 8" x  1/4"         8" x 8" x 3/8"

Square Flanges :

1" Sq           1 1/4" Sq

1 1/2" Sq      2" Sq

* various weld tabs for multiple applications