Good to know. I think all of the equipment at my job is 318 stainless, which is non-magnetic (I work in the mix area of a personal care/cosmetics plant). Needles are generally 304 which is generally non-magnetic.
304 is the most common needle material followed by 316
Practical implications for removal of stainless steel particles
Both 304 and 316 stainless steel possesses paramagnetic characteristics. As a result of these properties small particles (approx. 0.1-3mm dia sphere for example) can be attracted to powerful magnetic separators positioned in the product stream. Depending upon their weight and specifically their weight ratio to magnetic attraction, these small particles will be held to the magnets during the production process.
These can then be removed during the magnet cleaning operation. From our experience 304SS small particles are more likely to be held in the flow than 316 SS particles due to its slightly more magnetic nature.
https://www.microgroup.com/understand-magnetic-properties-304-316-stainless-steel/