1/2" Thick 3.5" x 2.5" D-Pipe Internal Mounting Pad | 3 Tapped Holes | D3 Profile | Marine Grade 6061-T6
0015
Internal Mounting Pad for D3 D-Profile Pipe
1/2" thick marine-grade 6061-T6 aluminum internal mounting pad designed to weld inside D3 D-profile pipe. Three tapped holes thread fasteners directly into the pad — no nuts required — creating the cleanest possible installation where the pipe appears to enter the fiberglass surface with zero visible hardware. The larger profile suits installations where the D-pipe is cut at more acute angles (up to ≈120°) — the extra surface area bridges the wider contact area inside the pipe at steeper approaches. Used on T-tops, instrument pedestals, and fiberglass leaning posts.
| Material | Marine Grade 6061-T6 Aluminum |
| Outer Dimensions | 3.5" × 2.5" |
| Thickness | 1/2" (0.500") |
| Mounting Holes | 3 Tapped (threaded) |
| Pipe Profile | D3 D-Profile |
| Install Method | Welds inside pipe — screws thread from inside fiberglass |
| Shape | D-Profile (internal match) |
| Finish | Matte — weld-ready |
| Weight | 0.199 lb |
Common Applications
Instrument pedestals, fiberglass leaning posts and seats, T-top leg mounts, tower mounts, and any fiberglass structure where a D-profile pipe needs to appear flush against the surface with no visible fasteners on the outside.
Frequently Asked Questions
What does "Internal Mounting Pad" mean?
This pad welds inside the D-profile pipe. Screws come from inside the fiberglass structure and thread directly into the tapped holes — no nuts or backing plate needed. The result is a clean install where the pipe appears to go directly into the fiberglass surface.
What does D3 mean?
D3 refers to the D-profile pipe size this pad matches — a 3" wide D-shaped aluminum profile commonly used in T-top and tower construction.
Why is this pad larger than the 3" x 2" version?
The larger 3.5" x 2.5" profile is designed for D-pipe installations cut at more acute angles (up to ≈120°). At steeper pipe cuts, the pad needs extra surface area to bridge across the wider inside contact area and still provide enough weld surface and thread engagement.
Do I need a backing plate with this pad?
No. The tapped holes accept fasteners directly — no backing plate or nut required. This is a standalone mounting point.
How is this different from a grommet pad or countersunk pad?
Grommet and countersunk D-pipe pads mount on the outside of the pipe with through-holes. This internal mounting pad welds inside the pipe with tapped holes, so fasteners thread into it from inside the fiberglass — no visible hardware on the finished surface.
- Local pickup available
- One Business Day Shipping
- Call us Mon.-Fri. 9:00 a.m. to 4:00 p.m. if in any doubt.
Due to this item's size and weight we can only ship it in an economical way via Less Than Truckload (LTL) consolidated land shipping, and only to the contiguous 48 States.
For shipping inquiries to AK, HI, PR, US-VI, and international shipping, please contact us first at sales@weldingworldinc.com.
All of the destinations above we can only serve as a Free Carrier (or FCA) modality, that requires the customer to contract and pay for their carrier service of choice. We can still ship the item, but only to a warehouse/receiving office within the 48-contiguous States.
In plain terms what this means is that if you want to ship your product to any non-contiguous US territory or internationally, you, the customer, has to provide us with the warehouse address of the carrier that serves your locality with an address within the contiguous 48-US States, as we do not ship overseas on our own.
