Screws with metric tread

I m searching for: in istanbul and around.
1. screws with metric tread (3x6, 3x8, 3x10, 3x12, 3,5x6 e.g.).
2. thermoplastic and thermo-reactive plastics(polystirol, pvc, bakelite).
3. brass profiles (round 4,8 mm, rhomboidal)