Black Key Clamp Four Way Cross for 33.7mm Tube, Electrophoretic, Indoor, Size B

The black four way cross joins a mid or lower rail to an intermediate post on an indoor guard rail, with the post running straight through. The post passes through the central barrel, the rail is cut at the post and each end pushes into its own socket, and three grub screws lock all three tubes. It suits 33.7mm outside diameter tube and is malleable cast iron with a black electrophoretic coat, a smooth dark finish for interiors. It is for indoor use only. The price shown is for one fitting, with a minimum order of 5.

Why use a four way cross

A level mid rail at every post. On a two-rail guard rail the top rail sits on short tees on top of the posts. The mid rail needs a joint partway up each post, and the four way cross gives it, keeping both rail ends exactly in line.

Posts stay in one piece. The post passes straight through, so it stays full length from floor to top rail. Only the mid rail is cut, into post-to-post lengths.

A neat dark finish. The black electrophoretic coat suits black tube in shops, showrooms, cafés, offices and homes, where a guard rail is on show.

No welding. Everything goes together with a hex key, inside an occupied building, with no fumes or sparks.

Where it is used

Indoor mezzanine and balcony guard rails, staircase landings, queue and divider rails in cafés, cinemas and shops, office and reception partitions, display frames, and black tube furniture and shelving.

Specifications

Indoors only

Electrophoretic coating is a thin, even paint layer that looks smart but does not protect the iron outdoors. Do not use this fitting outside or in wet areas: it will rust. For an outdoor black rail, choose powder coated fittings and seal the screws; for outdoor rails with no upkeep, choose galvanised.

Which black 33.7mm fitting goes where

How many do you need?

One four way cross for each intermediate post on each lower rail. End posts use a mid rail corner or short tee instead.

Choosing the right size

Key clamps are sized by the tube's outside diameter. 33.7mm tube is often sold as 1" or 25mm nominal bore. Measure across the tube: this cross will not grip 32mm or 42.4mm tube. The same fitting for 26.9mm tube: black 26.9mm four way cross. For a high-visibility rail: yellow 33.7mm four way cross.

Fitting and care

Slide the cross onto the post at mid-rail height before fitting the top tee. Cut each mid rail to the post spacing less the two socket depths, deburr the ends and push them fully home. Level the rail, then tighten all three grub screws with a 1/4" hex key. Take care not to scratch the coating with the key; touch up chips with black paint. Wipe clean with a damp cloth. Check the screws after the first week and once a year.

Frequently asked questions

Ordering and delivery

Order 5 or more online, with Express UK Delivery to your site and same-day dispatch on orders before 2pm, Monday to Friday. For a full black rail kit, call 01744 520 110 or email sales@industrialsuppliesco.co.uk and we will confirm availability and delivery before you order.