18/8 or 18/10 is short for 18 percent chromium and 8 or 10 percent nickel, in your country called 304 or the like. DIN number is 1.4301 so no troubles to get anywhere. The easy machining type 1.4305 got a bit of sulphur in the alloy, don´t know this type in AISI standard but somebody here will know. No worry about using them on girder forks as the Spares Co most likely got same types for spindles. I had discussions in other forums with scaremongers wanting to tell it was risky to use on girders but in fact shear strength is way higher than what you ever will feed into the girder. Before literally hitting near to shear strength for spindles you will have a flatted tire, springs on block , spokes broken - and yourself catapulted into the greenery . . . .
Vic
Vic