This is our Heavy Duty, all-purpose fishing, T-Bar.  It is an all weld design that requires no assembling of the T-Bar itself.  Simply mount the base anywhere on your boat and attach the T-Bar, using two(2) 3/8-16 Hex Bolts.  These T-Bars use 1 1/2" square aluminum tubing as the post, and uses 1 1/2"x1/2" aluminum flat bar as the T-Bar base and the T-Bar top.  Pletnty strong enough for Catfishing, but also low-profile enough for an excellent Crappie fishing setup.
 
As for mounting thread options for your holders, you can select between 3/8-16, 1/2-13 Right Hand, and 1/2-13 Left Hand  thread series.  There are five(5) total mounting positions on the top, so you can evenly mount three(3) rod holders or evenly mount four(4) rod holders.
 
Included, is all the Stainless Steel Hardware that is needed to mount the T-Bar as well as the bottom plate for the mount base, for when extra strength is needed.
 
All Weld Design
3 or 4 Holder Positions
Rigid 1 1/2" Aluminum Tubing Post
Strong 1 1/2x1/2 Aluminum Flat Bar for mounting base and T-Bar base
Also includes, a bottom plate for added strength for mounting underneath the base
Hardware included: 4 of 1/4-20 countersunk screws for the base, 4 of 1/4-20 hex nuts, 4 of 1/4" locking washers, 2 of 3/8-16 hex bolts for mounting the T-Bar, and 2 of 3/8" washers.