Key Clamp Short Tee Reducer for 33.7mm Post and 42.4mm Rail, 90° Galvanised

A 90 degree short tee with two different bores, for joining a 33.7mm post to a 42.4mm rail. The socket at the bottom takes the post and the barrel across the top takes the rail, which passes straight through. Each tube is held by its own hex socket grub screw, so the fitting locks on without welding or threading. Use it where the rail needs to be a larger tube than the post. The post bore is 33.7mm and the rail bore is 42.4mm, both across the outside of the tube. The post and the rail cannot swap places, because each bore fits only its own size. The fitting is galvanised malleable cast iron. The price shown is for one fitting, with a minimum order of 10.

Why a reducing tee works

Two tube sizes in one fitting. Without a reducer you would have to change the whole frame to one size or pack out the smaller tube inside a larger fitting. Here both bores are made for a standard tube size, so each tube sits in a bore that fits it.

No hot work. Cut the tube, slide it in and tighten the screw. There is no welding, no fire permit to arrange and no galvanising to repair on site.

Adjustable until you tighten it. The rail can slide through the barrel while you line it up, and the post can be set to height before the screws go tight. If the frame has to change later, slacken the screws and move it.

In short: two tube sizes, one fitting and no welding.

Where it is used

Straight and level guard rails on walkways, mezzanines, loading bays and around plant, at the point where a vertical post meets the top rail or a lower rail, including the end of a run and intermediate posts. It suits a frame where the rails are the larger section, such as a heavier top rail on lighter uprights. Because the barrel sits at 90 degrees to the socket, this is a fitting for level runs. On a stair or ramp you need a sloping fitting.

Specifications

Choosing the right reducer

Measure both tubes with a caliper before you order and check which one is the post. This tee is for a 33.7mm post and a 42.4mm rail. If your post and rail are the same size, you do not need a reducer, and an equal short tee is the right part.

See the full range of galvanised key clamp fittings.

Fitting and care

Cut the tube ends square and remove any burr, because a sharp edge stops the tube seating. Push the 33.7mm post fully home into the socket, then slide the 42.4mm rail through the barrel and line it up. Tighten each grub screw with a hex key until it bites firmly on the tube, and do not overdrive it. Tubes cannot be joined end to end inside the barrel, so plan rail joints at a separate fitting.

No load rating is published for this line. If the frame has to meet a design loading, have it assessed by a competent person before it goes into use.

Check the grub screws during routine inspections of the frame, especially where it is exposed to vibration. Galvanising needs no routine care in normal conditions, and any cut tube ends or damaged areas can be touched up with a zinc-rich paint.

Frequently asked questions

Ordering and delivery

Order 10 or more online, with Express UK Delivery to your site and same-day dispatch on orders before 2pm, Monday to Friday. For a larger job, call 01744 520 110 or email sales@industrialsuppliesco.co.uk and we will confirm availability and delivery before you order.