{"product_id":"d3-3-5-x-2-5-internal-mounting-pad","title":"1\/2\" Thick 3.5\" x 2.5\" D-Pipe Internal Mounting Pad | 3 Tapped Holes | D3 Profile | Marine Grade 6061-T6","description":"\u003cp style=\"font-size:1.15em;line-height:1.4;margin-bottom:0.75em;text-transform:none;color:#4a7ab5\"\u003e\u003cstrong\u003eInternal Mounting Pad for D3 D-Profile Pipe\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp style=\"font-weight:400;font-size:0.9em\"\u003e1\/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.\u003c\/p\u003e\n\n\u003ctable style=\"font-size:0.9em\"\u003e\n\u003ctr\u003e\n\u003ctd style=\"background-color:#1a1a1a;text-transform:none;color:#ffffff\"\u003e\u003cstrong\u003eMaterial\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"font-weight:400\"\u003eMarine Grade 6061-T6 Aluminum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background-color:#1a1a1a;text-transform:none;color:#ffffff\"\u003e\u003cstrong\u003eOuter Dimensions\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"font-weight:400\"\u003e3.5\" × 2.5\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background-color:#1a1a1a;text-transform:none;color:#ffffff\"\u003e\u003cstrong\u003eThickness\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"font-weight:400\"\u003e1\/2\" (0.500\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background-color:#1a1a1a;text-transform:none;color:#ffffff\"\u003e\u003cstrong\u003eMounting Holes\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"font-weight:400\"\u003e3 Tapped (threaded)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background-color:#1a1a1a;text-transform:none;color:#ffffff\"\u003e\u003cstrong\u003ePipe Profile\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"font-weight:400\"\u003eD3 D-Profile\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background-color:#1a1a1a;text-transform:none;color:#ffffff\"\u003e\u003cstrong\u003eInstall Method\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"font-weight:400\"\u003eWelds inside pipe — screws thread from inside fiberglass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background-color:#1a1a1a;text-transform:none;color:#ffffff\"\u003e\u003cstrong\u003eShape\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"font-weight:400\"\u003eD-Profile (internal match)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background-color:#1a1a1a;text-transform:none;color:#ffffff\"\u003e\u003cstrong\u003eFinish\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"font-weight:400\"\u003eMatte — weld-ready\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background-color:#1a1a1a;text-transform:none;color:#ffffff\"\u003e\u003cstrong\u003eWeight\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"font-weight:400\"\u003e0.199 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003cp style=\"text-transform:none;font-weight:600;font-size:1.05em;color:#4a7ab5\"\u003eCommon Applications\u003c\/p\u003e\n\u003cp style=\"font-weight:400;font-size:0.9em\"\u003eInstrument 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.\u003c\/p\u003e\n\n\u003cp style=\"text-transform:none;font-weight:600;font-size:1.05em;color:#4a7ab5\"\u003eFrequently Asked Questions\u003c\/p\u003e\n\u003cp style=\"font-weight:400;font-size:0.9em\"\u003e\u003cstrong\u003eWhat does \"Internal Mounting Pad\" mean?\u003c\/strong\u003e\u003cbr\u003eThis 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.\u003c\/p\u003e\n\u003cp style=\"font-weight:400;font-size:0.9em\"\u003e\u003cstrong\u003eWhat does D3 mean?\u003c\/strong\u003e\u003cbr\u003eD3 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.\u003c\/p\u003e\n\u003cp style=\"font-weight:400;font-size:0.9em\"\u003e\u003cstrong\u003eWhy is this pad larger than the 3\" x 2\" version?\u003c\/strong\u003e\u003cbr\u003eThe 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.\u003c\/p\u003e\n\u003cp style=\"font-weight:400;font-size:0.9em\"\u003e\u003cstrong\u003eDo I need a backing plate with this pad?\u003c\/strong\u003e\u003cbr\u003eNo. The tapped holes accept fasteners directly — no backing plate or nut required. This is a standalone mounting point.\u003c\/p\u003e\n\u003cp style=\"font-weight:400;font-size:0.9em\"\u003e\u003cstrong\u003eHow is this different from a grommet pad or countersunk pad?\u003c\/strong\u003e\u003cbr\u003eGrommet 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.\u003c\/p\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Product\",\"name\":\"1\/2 Inch Thick 3.5\" × 2.5\" D-Pipe Internal Mounting Pad with 3 Tapped Holes for D3 Profile\",\"sku\":\"0015\",\"mpn\":\"0015\",\"brand\":{\"@type\":\"Brand\",\"name\":\"Welding World\"},\"description\":\"1\/2 inch thick 3.5\" × 2.5\" 6061-T6 aluminum internal mounting pad for D3 D-profile pipe. 3 tapped holes for clean flush installations at acute pipe cut angles up to 120 degrees. 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