316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm
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316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm

316 Stainless Steel 90-Degree Tube Flange Base – Marine Railing Stanchion Mount, 22–38mm

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Price:
$35.15 USD
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In stock (500 units), ready to be shipped

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Description

316 Stainless Steel 90-Degree Tube Flange Base — Corrosion-Proof Marine Railing Mount for Round & Square Tube

Railing posts that wobble, base fittings that rust through after a single season, and hardware that simply wasn’t designed for saltwater exposure — these are the failure points that marine builders, boat owners, dock contractors, and coastal deck installers run into when they use the wrong grade of stainless. This 316 stainless steel 90-degree tube flange base is cast and machined from Grade 316 alloy throughout, giving you a corrosion-resistant, structurally sound stanchion mount that holds up in continuous saltwater spray environments without pitting, staining, or seizing.

Each unit is a single fitting sold individually. The product line covers two fitting categories: 90-degree base flanges (round tube socket or square tube socket, with a rectangular bolt-down base plate) and straight inline connectors (round tube, no base plate). Base flange variants are available for tube outer diameters of 22mm (7/8"), 25mm (1"), 30mm (1-3/16"), 32mm (1-1/4"), and 38mm (1-1/2"). Straight connector variants cover 22mm, 25mm, 30mm, and 32mm round tube. Base plate dimensions for the 90° flanges range from 79×44mm (3.1"×1.7") on the 22mm size up to 87×52mm (3.4"×2.0") on the 32mm size. Socket height (C) is 43–45mm (1.7–1.8") depending on size. Stainless steel mounting screws are included.

These fittings are the right choice for a boat deck railing stanchion base where the post must stand perfectly vertical from a horizontal deck surface; a dock or pontoon handrail post mount where the fitting will be submerged or continuously wetted by tidal water; and a pool deck or coastal balcony railing system where chloride exposure from pool chemicals or sea air demands marine-grade corrosion resistance rather than standard 304 stainless.

⚓ Compatible with: Round tube OD 22mm / 25mm / 30mm / 32mm / 38mm and square tube 22mm / 25mm / 30mm / 32mm. Fits standard marine railing tube, schedule pipe, and architectural handrail tube of the matching nominal OD. Select your tube profile and size from the Type option above.
⚠️ Size Confirmation: Always measure your tube’s outer diameter (OD) before selecting a variant. The socket bore is sized to the tube OD, not the tube’s nominal pipe size (NPS). If your tube OD falls between two sizes, contact us to confirm the correct fit before ordering.

✅ Key Features of These 316 Stainless Steel Tube Flange Bases

  • ⚓ Grade 316 Stainless Steel Throughout — The molybdenum content in 316 alloy provides significantly better resistance to chloride pitting and crevice corrosion than 304, making this the correct specification for saltwater marine railing hardware, dock fittings, and coastal handrail systems.
  • 📐 True 90° Vertical Socket Angle — The socket is machined at a precise 90° angle to the base plate, ensuring your stanchion post stands perfectly plumb from a horizontal deck surface without shimming or adjustment — critical for boat deck railing stanchion mounts and pool fence post bases.
  • 🔧 Dual Set-Screw Collar Retention — Two set-screw holes in the socket collar allow the tube to be locked in place at the correct insertion depth using a hex key. For permanent marine handrail post installations, apply thread-locking compound to the set screws to prevent vibration-induced loosening.
  • 🔩 Countersunk Base Plate with 4 Bolt Holes — The rectangular base plate has four countersunk corner holes that accept flush-head fasteners, keeping the mounting surface clean and snag-free. Stainless steel screws are included, ready for installation on fiberglass boat decks, teak decking, and composite dock surfaces.
  • 📰 Round & Square Tube Variants in One Product Line — Base flange variants are available for both round and square tube profiles in the same size range, letting you match the fitting to your existing railing tube profile without sourcing from multiple suppliers for a mixed-profile deck railing system.
  • 🔗 Straight Connector Variants for Inline Tube Joining — The straight connector variants join two sections of round tube end-to-end without a base plate, useful for extending a railing run or repairing a damaged section of an existing stainless marine handrail system without replacing the entire rail.

📐 Technical Specifications — 316 Stainless Steel 90° Tube Flange Base

Material Grade 316 Stainless Steel
Finish Mirror-polished
Fitting Angle 90° (tube socket perpendicular to base plate)
Compatible Tube Profiles Round tube and square tube (see Type variant)
Available Tube Sizes 22mm (7/8") / 25mm (1") / 30mm (1-3/16") / 32mm (1-1/4") / 38mm (1-1/2")
Socket Bore (D) — 22mm variant 22.5mm (0.89")
Socket Bore (D) — 25mm variant 25.5mm (1.00")
Socket Bore (D) — 30mm variant 30.5mm (1.20")
Socket Bore (D) — 32mm variant 32.5mm (1.28")
Base Plate Length (A) — 22mm 79mm (3.1")
Base Plate Length (A) — 25mm 82mm (3.2")
Base Plate Length (A) — 30mm 86mm (3.4")
Base Plate Length (A) — 32mm 87mm (3.4")
Base Plate Width (B) — 22mm 44mm (1.7")
Base Plate Width (B) — 25mm 47mm (1.9")
Base Plate Width (B) — 30mm / 32mm 52mm (2.0")
Socket Height (C) 43–45mm (1.7–1.8") depending on size
Base Plate Mounting Holes 4 × countersunk holes at corners
Tube Retention 2 × set screws (hex key tightened)
Included Hardware Stainless steel mounting screws
Primary Application Marine / yacht / boat deck railing, dock handrail, pool fence, coastal balcony
Sold As Single fitting (1 piece per order)

❓ Frequently Asked Questions

How do I choose the correct tube size for my railing?

Measure the outer diameter (OD) of your tube in millimeters using calipers or a tube gauge. The socket bore (dimension D) is slightly larger than the nominal tube OD to allow the tube to seat fully: the 22mm variant has a bore of 22.5mm, 25mm → 25.5mm, 30mm → 30.5mm, 32mm → 32.5mm. Always measure your actual tube OD before selecting a variant — do not rely on nominal pipe size (NPS) designations, which differ from OD measurements.

What is the difference between the Round Tube Base and the Square Tube Base variants?

The Round Tube Base has a cylindrical socket designed to accept round tubing of the matching OD. The Square Tube Base has a square-profile socket designed to accept square section tubing of the same nominal size. Both types mount to a flat surface via the same rectangular base plate with four countersunk bolt holes. Select the variant that matches your tube’s cross-section profile.

What is the Straight Connector variant used for?

The Straight Connector is an inline tube-to-tube coupler that joins two sections of round tube end-to-end in a straight line. It does not include a base plate and is not a floor-mount fitting. Use it to extend a railing run, bridge a gap between two tube sections, or repair a damaged section of an existing stainless marine handrail without replacing the full rail.

Is 316 stainless steel suitable for saltwater marine environments?

Yes. Grade 316 stainless steel contains molybdenum, which significantly improves resistance to chloride-induced pitting and crevice corrosion compared to the more common 304 grade. It is the standard material specification for marine hardware, boat railings, dock fittings, and coastal architectural applications exposed to saltwater spray or immersion. For freshwater or inland applications, 316 provides additional corrosion margin beyond what is strictly required.

How is the flange base secured to the deck or surface?

The rectangular base plate has four countersunk bolt holes at the corners, allowing it to be fastened flush to any flat surface using countersunk screws (stainless steel screws are included in the package). The countersunk profile keeps fastener heads flush with the plate surface for a clean, snag-free finish. For fiberglass or composite decks, pre-drill pilot holes and use a backing plate on the underside to distribute load.

How is the tube secured in the socket?

The socket collar has two set-screw holes on the side. After inserting the tube to the correct depth, tighten the set screws using a hex key (Allen wrench) to clamp the tube firmly in place. For permanent installations or high-vibration environments (such as boat decks underway), apply a thread-locking compound such as Loctite 243 to the set screws before tightening to prevent loosening.

Can this fitting be used for handrails on stairs or balconies?

Yes. The 90° base mount is suitable for vertical stanchion posts on stairs, balconies, pool decks, and boat decks. However, for load-bearing handrail applications, ensure the base plate is fastened to a structurally sound substrate and that the fastener specification meets local building code or marine classification requirements. Consult a qualified installer or structural engineer if the railing is required to meet a specific load rating.

What base plate dimensions should I expect for each size?

Base plate dimensions (hand-measured, minor tolerances apply):

  • 22mm: Length (A) 79mm (3.1"), Width (B) 44mm (1.7"), Socket height (C) 44mm (1.7")
  • 25mm: Length (A) 82mm (3.2"), Width (B) 47mm (1.9"), Socket height (C) 43mm (1.7")
  • 30mm: Length (A) 86mm (3.4"), Width (B) 52mm (2.0"), Socket height (C) 45mm (1.8")
  • 32mm: Length (A) 87mm (3.4"), Width (B) 52mm (2.0"), Socket height (C) 45mm (1.8")
🛒 Select your tube type and size above, then add to cart.

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