BSP – BRITISH STANDARD PIPE

If you are buying spare parts for a traditional coffee machine, you are going to need to know your BSP, British standard pipe sizes. These are used in traditional machines and are not directly*1 related to the actual size of the OD thread on the part, which makes things confusing without the chart below.

The chart below designates commonly used BSP sizes used in coffee machines to what you actually measure in millimetres. So you can simply measure your existing part’s outer diameter and link it do the correct BSP size. Because the Italians use these as well, nobody is going to give you straightforward millimetre measurement. They will all specify parts in British standard pipe sizes. Rule Britannia.