There are so many variations of brush but the most important decisions you need to make are on size and bristle material.
Bristle material
The most essential part of your brush is the bristles. These need to be the right stiffness and material to ensure you can carry out your task easily and without damaging your pipe.
Consider what you need the brush to do. Do you need to prepare a metal joint for soldering? Or do you need to clean a plastic pipe?
As a general rule, metal bristles should be used to remove corrosion and to prepare metal surfaces and plastic bristles on plastic pipes and for general cleaning.
Another consideration when choosing the bristle material is: will you be using a cleaning agent? This could be water, soap or something stronger such as bleach or an acid.
Some bristle materials will be damaged in cleaning agents while others can be used in highly corrosive acids without worry. See What are pipe-cleaning brush bristles made of? for more information on the bristle materials available.
Size
The diameter of the bristles will be in the product description for a brush. If there is only one number present then it is the diameter of the bristles. Sometimes the length of the brush, stem or handle may also be written. All lengths will be in millimetres.
Ideally a pipe-cleaning brush should be slightly larger in diameter than the pipe. This is easily achieved by buying a pipe-cleaning brush that is described as having the same diameter as the pipe to be cleaned, for example, you can buy a 22mm (⅞”) brush to clean a 22mm copper pipe. This is because 22mm is the external diameter of the copper pipe and the internal diameter is actually 20.2mm (it has a wall thickness of 0.9mm).
Other measurements that may affect your decision on which brush you choose include fill length (length of the bristles from the stem outwards), stem or core diameter and thread size (written in millimetres preceded by ‘M’ or using the British Whitworth Standard, preceded by ‘W’).
The denseness of the bristles can be increased by choosing a double-wound stem but remember that double-wound stems are thicker and may not fit into the tube you need to clean.
Brushes can be bought singly or in a set of various sizes or bristle material.
Still not sure?
Pipe-cleaning brushes are available in almost every size and shape you could require but it is sometimes hard to find the one you want with so many options and names. Talking to your supplier about what you need may help you narrow down the choices.
Some manufacturers offer to produce a brush to any specification you require but the most common ones are readily available on the market. If the brush you want is not on the shelf in your local shop they may be able to order the size you need through their supplier.