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.

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.

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.

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.

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.

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.

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.

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")