https://pinside.com/pinball/forum/topic/shortage-of-premium-balls-for-magnet-pins

Ball Baron

https://pinside.com/pinball/forum/topic/ninja-ball#post-4157229

I’ve been using them in my games with magnets with no issues but he does have carbon steel balls that are very very shiny as well.

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I have been using Marco 5 pinball pack for years in pinball machines that use magnets . There are packed it oil and are the best wash oil off with soap and water . Pinball life Terry has great items do not get me wrong . However .I have received pinballs that have swirl marks from Pinball Life more than once . Never with Marco pinballs $4.95 5 pack .
www.marcospecialties.com

I got Ball Baron balls that were COMPLETELY FUCKED by magnets, so just be careful.

But they wern't the carbon core balls right.

Apparently not. Carbon Cursed maybe. Cursed Core? I just want shiny balls that work, people, is that too much to ask? I walk the streets, shouting about it.

I would not use the Crome ninja any machine with magnets in them and expect them not to turn into magnets. The carbon steel balls look fantastic. I plan testing Crome ninja in my CSI just to see. I think I will do that right now.

Hmmm... after running the crome ninja over the magnet which is pain in ass restarting the machine every time. I did it 100 times after 25 it seemed real magnetic. I was picking up .380 of inch ball bearing and thought the ball was going to get super magnetic. I ran it through 25 more times and it seemed less magnetic. I ran it through about 10 more times and seemed to be rejecting the machine magnet twice in row. It still was stuck both times but was making a chattering noise. The other 38 times were normal. All in all...yes your Crome ninja balls are going to get magnetic with magnets in your machine. How that effects your machine I have no idea. I personally would stick to carbon steel with machines with magnets.

Shiniest chrome core ball that exists on the market:
https://ballbaron.com/product/ninja-super-shiny-chrome-pinball-g10/

Shiniest carbon core ball that exists on the market:
https://ballbaron.com/product/pinball-carbon/

If you change your balls frequently, i.e. when they start to scratch up a bit, get the Ninja chrome balls even with magnet games. They generally will become magnetized enough to notice just around the time they should be changed out. The carbon balls won't magnetize for a very long time but they are softer and scratch much faster.

If you had to guess how long would the ninjas last in a home environment on magnetic games?

I bought a bunch and was worried about using them.

So I have them in all of my games, and the magnetic ones would be TAF, Dialed In, Metallica, and Dr. Dude.

I don't anticipate Dr. Dude being an issue as it only has a single small magnet that isn't used frequently.

TAF's power magnets never touch the ball and will not create magnetism. The only time they touch a magnet is Thing's hand and it's infrequent, so I don't suspect any issues. Also, the ball doesn't rub the magnet, it's simply picked up and dropped. I have several hundred games on TAF with them and have no issues nor do I expect any prior to their periodic replacement.

Metallica and Dialed In both use magnets pretty heavily and do cause the ball to rub them frequently. On Metallica, no issues after hundreds of plays except if multiple balls are caught by Sparky at once, they stay there once the magnet turns off. A slight bump breaks them free. No other issues.

On Dialed In, I am finally starting to see magnetism issues after several hundred long plays. Because QED guy has a metal base they occasionally stick to it if they happen to rest near it. A gentle bump frees them. They are at the point where I'd replace them though so that issue will be reset when I do.

Bottom line is if your game doesn't cause the ball to rub on the magnet core often, it's far less likely to occur. If you change your balls every few hundred games or less, magnetism shouldn't be an issue in most games. If you tend to keep the balls in your game for a while, chrome balls will eventually magnetize.