What is a garden tap thread size in the UK?

The standard garden tap thread dimension in the UK is sized according to the British Standard Pipe standard.  The outside diameter of the threaded connection on the tap is NOT the measurement that is relevant because BSP fittings always refer to the internal diameter of the pipe they fit. 

Garden tap thread size UK is 3/4" BSP

The most standard tap thread for domestic garden taps in the UK is 3/4" BSP (British Standard Pipe).  This measures 26.44mm across the outside diameter - roughly 1"  The picture shows the measurement for a standard 3/4" tap thread.  If your tap looks like this, you have a standard 3/4" BSP tap.

It is a very common mistake to assume that the 1" outside diameter measurement means you have a 1" BSP tap.  The 1" BSP size is intended for commercial installations and very large gardens requiring large volumes of water.  If you have an average sized domestic property, it is unlikely that you have a 1" BSP tap. The diameter of this tap will be well over 30mm, so don't waste your money on a purchase of a commercial sized 1" connector - it won't fit your tap.

Quality tap connector are recommended

The 3/4" Gardena tap adapter  is likely to be the correct fitting for the majority of gardens.  However, you may prefer to pay a little more for the very best quality metal tap connector, in which case have a look at the Gardena Premium Connector 18241-20  This connector is robust and produced in Germany to the highest standards - it will not let you down.

Older houses have a different garden tap thread size in the UK

If you have a slightly older tap, it may be a 1/2" BSP thread version and Gardena supply an adapter to convert the 3/4" fitting to fit these.  The older 5/8" threaded tap is very rare and a special fitting would be required to fit; or maybe it's time for a new tap. 

Table of tap thread sizes

You can refer to the table below where we have shown the outside diameter measurement for each UK standard tap size.  These sizes will not apply to taps purchased or fitted outside of the UK.

Please remember, a rubber washer is required between the tap and the fitting and also between the adapter (if used) and the fitting, to ensure that there are no leaks.

1/2" BSP threaded tap measures 20.99mm Outside diameter

5/8" BSP threaded tap measures 22.99mm Outside diameter

3/4" BSP threaded tap measures 26.44mm Outside diameter

1"    BSP threaded tap measures 33.25mm Outside diameter

Once you have measured and confirmed your thread size you will be able to purchase a tap connector with confidence.  A complete range of high quality Gardena indoor and outdoor tap connections is available.

Buy a good quality hose connector

Once you have sorted out a correctly sized tap fitting, don't waste money on cheaper inferior connectors and hose pipe - they will let you down. View the complete Gardena range here at Mincost. Quality is cheaper in the long run.

Click on the image below for everything you need to connect a hose to your garden tap