It depends on what sort of arm you have, push fit or screw in (fender style). With a push fit i put a very thin coat of nail varnish on the part that fits in the trem, this will tighten it up and keep it i place. On a screw fit arm i put a spring (out of a pen) in to the hole before i screw the trem arm in, be careful that you dont over tighten the arm. Hope this helps.