Cartridge mount screws - stainless steel


I need longer mount screws to mount my cartridge, can i use plain steel screws or must i use stainless steel screws . I am having a hard time finding small stainless srews, 20 mm long locally.
tshulba
So, what's the right size? 2.5 mm? Elusivedisc carbon fiber Shelter screws are 2 mm.
Just an update- Mapleshade sells brass mounting screws in 2.5x16 mm size with nuts.
I ordered two pairs, should be "under $5 per pair", I've been told.
They also recommend Nanomount system, which you can see on the Mapleshade website, which should "drastically improve cartridge performance".
Anyone tried Nanomount system yet?
Maril555 i have been using Nanomount and Lp Coupling systems with my Aries Three. Both are a real step up for better sound from your lps improved detail, air, clarity. I will be selling the coupling system and Aries as i have moved in another direction turntable wise if you are interested.