Over 800 different types of perforations and metals on  stock. Micro perforations from 5 mµ in stainless steel.
Perforation type - For Sieves and filters round hole perforations, pattern RT, and square hole perforations, pattern CU, are often used as support material. Both perforations in various hole sizes and material thickness are available. 
Pitch - Centre-to-centre distance between
two adjacent holes.
Strand - The smallest distance between
two adjacent holes.
Hole - The smallest possible hole size depends on metal type and material thickness.
Open area - Is calculated based on the following
formulas:
Round hole: 90,7x(R:T)²
Square hole: 100x(C:U)²
Sieve direction - The standard sieve direction is
parallel to the short side of the sheet material

Over 300 different types of apertures and metals on stock. Sieves and filters will be made with wire-mesh according to your specifications.
Plain weave - Excellent sieving qualities
Apertures from 20 mµ - 15 mm.
Single/double intermediate crimp screen - Stable mesh with pre-formed wires. Also used as a support material. Apertures : 8-100 mm.
Twilled weave - Excellent sieving qualities and very
strong. 
Apertures 25-1000 mµ.
Single plain weave - Twill weave, good flow. Thicker warp, thinner weft.
Open area 30-350 mµ.
Reverse Dutch twilled weave - High bursting strength. Good flow
characteristics. Open area 16-600 mµ.
Dutch twilled weave - Relatively light filter mesh.
Open area 5-110 mµ.

Meshes from 150 mµ to very large meshes in various metals. Over 75 different types on stock. Often expanded metal is used as support material. 

Synthetic Wire-mesh

Over 750 different types of filtration mesh (a.o. antistatic) and filter cloth available in nylon, polyester, polypropylene, Teflon and various special executions from 1 mµ to 5 mµ.