Not every bar or chain is right for every saw. ... That's why electric saws use bars 18" and shorter. Similarly, chainsaw chains are measured to fit certain bars. Try to fit a chain onto a bar that's too narrow or too long, and you'll find that your saw simply won't work.

Can you use any brand chain on a chainsaw?

Mixing brands of chains is no problem, provided you use compatible chains. I'm no longer able to buy "original" chains for my old Homelite so I buy it off the roll at the local mower/chainsaw dealer, who also joins it up for me.

Are all chainsaw chains universal?

Chainsaw bars and chains come in all different sizes and lengths, so you can't just buy any old type at the store and expect them to fit on the chainsaw you have at home. The most important thing you'll want to do is to check the manufacturer's specifications for your particular brand and model of chainsaw.