All pinball machines use a standard 1-1/16″ Inch (27 mm) steel ball. Vintage woodrail pinball games typically used five pinballs. Then in the 60s they introduced automatic ball return so they only needed one pinball. Once multiball was introduced in the 80s, pinball machines started using 2, 3, 4 and even 13 pinballs.
Nothing will ruin a pinball machine’s playfield faster than a rusty, scratchy old ball. A pitted, rusty old pinball is like a rolling sheet of sandpaper. Whenever you purchase an old pinball machine, inspect the pinball and replace your pinballs every year or more often depending how much it is played.
Replacement steel pinballs are cheap insurance for the longevity of the artwork on your pinball machine. Regular cleaning and waxing of the playfield surface along with the replacement of the pinballs when they get scratched will prevent wear of the artwork. This is especially true of newer games with faster speed and multiball modes where the pinballs crash into each other more often and at higher velocities.
Pinball machines that include magnets as part of the feature mix can also magnetize your pinballs which can cause all sorts of problems in the ball trough. For these games choose special pinballs that resist being magnetized or replace more often.
Replacement pinballs for pinball machines are cheap. Order a bunch to have on hand and mark your calendar for regular replacement and if your machines have batteries on the circuit boards, be sure to replace them also so you don’t have leakage which can lead to expensive board repair or replacement.