Tubeclamp tube fitting products are designed to work with various tube diameters, ranging from 21mm to 114mm. Our fittings are specifically made to fit standard sizes of galvanized steel tubes and some aluminum pipes. The most common fitting sizes we use are labeled T21, A27, B34, C42, D48, and E60. These labels are consistent across most Tubeclamp products. However, not every product will fit all sizes. A table detailing these sizes is provided below.

When we talk about the size of a tube that a fitting can accommodate, we usually use two terms.

1: Outside Diameter (OD), which shows the diameter of the tube’s outer surface.

2: Nominal Bore (NB), which indicates the diameter of the tube’s hollow inside.

For most applications, like scaffolding and handrails, we typically refer to fitting sizes using the OD description. However, for fence fittings, we often use the NB measurement instead.

Examples:

1: A Long Tee Fitting used to create a handrail with a 42mm outside diameter pipe would be TC104D or TC104 Long Tee C42 - 42mm OD (32NB) Pipe.

2: A fixed scaffolding coupler for a 48mm outside diameter scaffold pipe would be a SP DC48 or SP DC 48-48. The same coupler for 50mm or 51mm would be SP DC51.

3: A Tee fitting meant to secure the top rail of a fence with horizontal rails measuring 34mm in Outside Diameter (OD) and posts with an OD of 42mm would be listed on our website as ‘B34 OD (25NB) Tru x C42 OD (32NB) Butt.’ The product code for this item would be DF T2532.