The dual pipe bender is the most versatile of the benders as it has a number of different sized formers available to it. It can also fit two formers at a time, making it useful for site work as you do not have to carry multiple formers.
Ratchet pipe bender
The ratchet pipe bender is useful for people who have little body strength but need to bend quite thick or strong piping as it does not require any pulling force by the user.
However, the force caused by the former hitting the pipe can sometimes flatten it.
The ratchet pipe bender is the only pipe bender that can bend larger sized piping, over 10mm (0.4″) in small spaces, because it does not have long handles. This can be useful for site work where space may be limited.
Mini pipe bender
The mini and micro pipe benders are most suitable for people who only require a bender for small pipe diameters, under 10mm (0.4″), such as electrical piping. The mini bender is the most suitable kind of pipe bender for this type of piping as the conduit bender does not bend such small pipes.
Pipes under 10mm (0.4″) in diameter are also used often in heating applications e.g. for radiators and boilers.
Ergonomic pipe bender
The ergonomic pipe bender is supposedly easy to use because of its ergonomically-designed curved handles, however the benefit of this seems relatively small.
Furthermore, the ergonomic pipe bender is much more expensive than other hand-held pipe benders and is limited to only one former size, either 10mm (0.4″) or 15mm (0.6″).
Free-standing pipe bender
The free-standing pipe bender is most effective for bending thick walled or strong steel piping. This is because its two legs provide stability and allow the user to use two hands, giving more leverage when bending the pipe.
However, the free-standing pipe bender is not as useful as hand-held benders if you travel often with your bender (if you are a plumber for example) as it is bulky to transport.
Conduit pipe bender
The conduit pipe bender is specifically designed for bending conduit piping, however it only bends larger conduit piping of 20 and 25mm (0.7 and 0.9″) in diameter.
Also, bending on the floor can make seeing the angle markings difficult and mean that bends are less accurate.