316 Stainless Steel Open Tee Pipe Fitting — Detachable 90° Marine Handrail Connector for Boats & Yachts
Replacing or extending a handrail on a boat usually means disassembling the entire run just to add a single branch — removing end caps, sliding fittings off, and reassembling everything from scratch. For boat builders, marine outfitters, and yacht owners who need to add a grab rail or cross-member to an existing system without that hassle, this 316 stainless steel open tee pipe fitting clamps directly onto the rail at any point, no disassembly required.
Each set includes one open tee fitting with M6 set screws pre-installed. The body is precision investment-cast from marine-grade 316 stainless steel using a silica sol process and finished with a mirror polish. Two sizes are available: the 22.5mm model has an overall height (A) of 52mm (≈2.0"), width (B) of 52mm (≈2.0"), branch bore (C) of 22.5mm (≈7/8"), and set screw hole diameter (ØD) of 6.5mm (≈1/4"). The 25.5mm model measures A=55mm (≈2.2"), B=55mm (≈2.2"), C=25.5mm (≈1.0"), ØD=6.5mm (≈1/4"). Both models use the same open-sided branch socket design for tool-free lateral installation onto an existing tube.
This fitting is well suited for adding perpendicular grab rails to existing cockpit or deck handrail runs on sailboats and powerboats, building T-junction support structures on yacht bimini and dodger frames, and constructing or repairing stainless steel marine handrail systems on commercial and recreational vessels — anywhere a detachable 90-degree marine tube connector needs to hold securely without permanent modification.
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Fits 22.5mm (≈7/8") or 25.5mm (≈1.0") OD stainless steel tubing. Secured with M6 set screws (ØD 6.5mm). Suitable for marine handrails, grab rails, bimini frames, and yacht deck hardware. Measure your tube OD before selecting a size.
✅ Key Features of These 316 Stainless Steel Open Tee Pipe Fittings
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🔓Open-Sided Branch Socket — The split tee design lets you clamp the fitting onto an existing handrail tube from the side without removing end caps or disassembling the rail run — a significant time saver when adding a branch to an assembled marine handrail system.
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🔩316 Stainless Steel, Silica Sol Cast — Investment-cast using the silica sol process for a dense, uniform grain structure that resists the chloride corrosion and pitting that commonly affects marine tube fittings in saltwater environments.
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✨Mirror-Polished Finish — Hand-polished to a mirror surface that matches standard stainless handrail tubing aesthetically and reduces surface oxidation, keeping the fitting looking clean season after season on boats and yachts.
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🔧M6 Set Screw Clamping — Two M6 set screws (ØD 6.5mm holes) clamp the fitting firmly to both the main rail and the branch tube using a standard hex key — no welding, drilling, or special tools required for installation or repositioning.
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📐Two Sizes for Common Marine Tube Standards — Available in 22.5mm (≈7/8") and 25.5mm (≈1.0") bore to match the two most common stainless steel handrail tube diameters used on recreational and commercial marine vessels.
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🔄Detachable & Repositionable — Unlike welded or swaged fittings, this open tee can be loosened, repositioned, and re-tightened without damaging the tube — useful for adjustable deck layouts or temporary rigging on sailboats and powerboats.
📐 Technical Specifications — 316 Stainless Steel Open Tee Pipe Fitting
| Product Type |
Open Tee Pipe Fitting / Marine Handrail Connector |
| Material |
316 stainless steel (investment cast, silica sol process) |
| Surface Finish |
Mirror polished |
| Connection Angle |
90° tee (T-junction) |
| 22.5mm Model — Height (A) |
52mm (≈2.0") |
| 22.5mm Model — Width (B) |
52mm (≈2.0") |
| 22.5mm Model — Branch Bore (C) |
22.5mm (≈7/8") |
| 22.5mm Model — Set Screw Hole (ØD) |
6.5mm (≈1/4") |
| 25.5mm Model — Height (A) |
55mm (≈2.2") |
| 25.5mm Model — Width (B) |
55mm (≈2.2") |
| 25.5mm Model — Branch Bore (C) |
25.5mm (≈1.0") |
| 25.5mm Model — Set Screw Hole (ØD) |
6.5mm (≈1/4") |
| Fastening Hardware |
M6 set screws (included) |
| Quantity per Set |
1 open tee fitting with set screws |
| Recommended Applications |
Marine handrails, grab rails, bimini frames, yacht deck hardware, boat cockpit rails |
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Measure the outer diameter of your existing tubing before selecting a size. The open branch socket accepts the tube from the side — confirm the tube OD matches the fitting bore (C dimension) for a secure clamp. Contact us if you need help confirming compatibility.
❓ Frequently Asked Questions
How do I choose between the 22.5mm and 25.5mm sizes?
Measure the outer diameter of your existing handrail or grab rail tubing. The 22.5mm fitting (C dimension) is designed for tube with an outer diameter of 22.5mm (≈7/8"), while the 25.5mm fitting suits 25.5mm (≈1.0") OD tube. Always measure your tube OD before ordering — a fitting that is too loose or too tight will not clamp securely.
What does "open tee" mean, and why does it matter?
An open tee fitting has a split or open-sided socket on the branch port, allowing you to clamp the fitting onto an existing rail without removing end caps or threading the tube through. This makes installation and repositioning significantly faster than a closed tee, especially on assembled handrail systems on boats and yachts.
How strong is this fitting for handrail use?
The fitting is investment-cast from 316 stainless steel using a silica sol process, which generally produces a denser, more uniform structure than sand casting. The M6 set screws clamp the fitting firmly to the tube. For safety-critical handrail applications, always verify the assembled system meets your vessel's load requirements and applicable marine standards.
Is 316 stainless steel suitable for saltwater environments?
Yes. Grade 316 stainless steel contains molybdenum, which provides significantly better resistance to chloride and saltwater corrosion than 304 SS. It is the standard material for marine handrail fittings exposed to spray, splash, and humid sea air. The mirror-polished finish further reduces surface pitting over time.
What tube outer diameter does this fitting accept?
The 22.5mm model accepts tubing with a 22.5mm (≈7/8") outer diameter. The 25.5mm model accepts 25.5mm (≈1.0") OD tubing. Both models use M6 set screws (ØD 6.5mm holes) to secure the fitting to the tube. Confirm your tube OD before selecting a size.
Can I use this fitting on a straight run of rail as a mid-point branch?
Yes. The open tee design allows you to clamp the fitting onto any point along an existing straight rail without disassembling the run. The 90° branch port then accepts a perpendicular tube, making it ideal for adding a grab rail, support strut, or cross-member to an existing handrail system on a boat or yacht.
What tools do I need to install this fitting?
Installation generally requires a hex key (Allen wrench) to tighten the M6 set screws. No drilling or welding is required. Position the fitting on the tube, insert the branch tube into the 90° port, and tighten the set screws to clamp both tubes securely in place.
🛒 Select your size above, then add to cart — each set includes one open tee fitting with M6 set screws, ready to install.
