Stainless steel shot rusting?

So I thought stainless wasn’t supposed to rust.

I’ve had this shot for over 5 years, haven’t used it for over 2
months, went to tumble today and there’s rust in the bottom. It
seems some of the round shot is rusting… is this supposed to
happen? And can I clean it?

I store it in a container in water and a little soap, as per the
instructions I was given when I purchased it. I’ve never had a
problem before.

Amery Carriere

Check your shot with a magnet. some stainless steel is ferritic and
magnetic and can rust a little.

shot used for jewelry tumbling is usually an austenitic grade -non
magnetic and not normally rusting.

The austenitic grades usually encountered are series 304 and 316. You
can prevent wet ferritic shot from rusting by keeping it under
alkaline water.

You can keep the solution alkaline by adding a little washing soda
also called soda ash or sodium carbonate.

Your current “soap” may not provide enough alkalinity for rust free



I have two pounds of the mixed stainless media. The manufacture only
states that it is stainless but not which grade. I can only assume,
and I shouldn’t, that it is a type 304.

This stainless really shouldn’t ‘rust’. Although it can get
contaminated when used next to carbon steel.

When I recieved my shot it was rinsed after the first use and dried
on a paper towel. Next day rust was found on the towel. A magnet
found about 75 pieces of the shot were carbon steel. They somehow got
mixed in with the stainless.

I don’t use my tumbler very often so I always rinse and then dry the
shot for storage. I don’t know why they want you to store the shot
wet. I hope you find your problem.

Gary D.