Convex end cap

The Strofix convex end cap is an AISI 304 stainless-steel end cap with a gently curved outward profile, designed to close the open end of Ø42.4 × 2 mm or Ø48.3 × 2 mm railing tubes. The Ø42.4 variant has a 6 mm height; the Ø48.3 variant has an 8 mm height. Supplied in satin finish. The cap is installed by driving it into the tube bore (elements for driving included).

The convex shape creates a subtle outward curve that rises slightly above the tube face, providing a finished appearance with minimal visual prominence. The height scales with the tube diameter — 6 mm for Ø42.4 and 8 mm for Ø48.3 — maintaining consistent proportions across both tube sizes. The press-fit attachment means no adhesive or screws are required. Select the tube diameter in the dropdown at order time. The Ø42.4 × 2 mm size matches the standard Strofix railing pipe, and the Ø48.3 × 2 mm size matches the heavier-duty tube. AISI 304 stainless steel is suitable for standard interior and exterior installations.

The satin finish provides a uniform appearance that matches other Strofix satin-finished railing components.

Use cases:

• Subtly curved tube end closure on Ø42.4 mm and Ø48.3 mm handrail and railing post tubes
• Railing terminations where a flat cap is too minimal but a taller dome is not desired
• Handrail end finishing with a gentle convex profile for a refined appearance
• Staircase and balcony railing tube end closures with a low-profile curve
• Post tube top finishing on both standard and heavy-duty Strofix tube sizes

FAQ:

What tube sizes does this end cap fit?

Two tube sizes are available: Ø42.4 × 2 mm and Ø48.3 × 2 mm. Select the correct tube size in the dropdown at order time.

What is the cap height for each tube size?

The Ø42.4 variant has a 6 mm height (H = 6 mm). The Ø48.3 variant has an 8 mm height (H = 8 mm). The height scales proportionally with the tube diameter.

How does this differ from the single-tube convex end cap?

The single-tube convex end cap (SKU GK426S-04/242) fits only Ø42.4 × 2 mm at H = 6 mm. This product adds the Ø48.3 × 2 mm option at H = 8 mm. If you only need the Ø42.4 size, either product works; if you need the Ø48.3 size, use this product.

How does the convex profile compare to other end cap shapes?

The End Caps range offers four profile shapes for round tubes: flat press-fit (H = 2–3 mm, near-flush), convex (H = 6–8 mm, subtle curve), ellipsoid (H = 24–27 mm, moderate dome), and dome (H = 42 mm, hemispherical). The convex profile provides just enough curvature to be visible as a rounded closure without extending significantly beyond the tube face.

How is this cap installed?

The cap is installed by driving (pressing or tapping) it into the tube bore. This is a press-fit attachment — no adhesive or screws are used.

What steel grade and finish is used?

The convex end cap is manufactured from AISI 304 stainless steel with a satin finish. AISI 304 is suitable for standard interior and exterior installations.

About End Caps

An end cap is a stainless-steel closure piece that plugs into or fits over the open end of a railing tube, post or solid bar, sealing it against moisture ingress and giving the termination a clean, finished appearance. Without an end cap, the cut tube end is exposed — visually unfinished and prone to collecting water and debris inside the hollow section.

Strofix supplies 13 end cap products in three profile families: caps for Ø42.4 mm round pipe (available in flat, convex and ellipsoid shapes), caps for 40×40 mm flat square tube (flat profile), and caps for Ø10 and Ø12 mm solid crossbar rods.

All are in AISI 304 stainless steel with a satin finish, with AISI 316 and polished options available on selected variants. The correct end cap depends on the tube or rod profile it will close, and the desired cap shape.