100 years of Heinrich Schnarr GmbH / 1926 - 2026

Legal information / Catalogue of Requirements

Catalogue of Requirements for the Provision of Materials.

For optimal processing it is necessary to specify the delivered condition of the workpieces. The following requirements must be met:

1. Material

Exact material and hardness specifications
Homogeneous material structure
No cavities, pores, grinding marks, foreign matter, mill scale, cracks, damage
Rz < 2 μm
Avoid cavities and blind holes
No material distortion
Avoid different material combinations
No joints or overlaps
No contamination by corrosion products
No residues from mechanical pre-treatment
Welding seams should be continuous
Demagnetised

2. Pre-grinding

Prevent localised overheating
Apply sufficient cooling lubricant
No cooling agents containing silicone, molybdenum, graphite or sulphur
Avoid embedded particles by firing without infeed
No residual turning marks

3. Pre-polishing

No polishing agents containing silicone, molybdenum, graphite or sulphur
Improper polishing leads to grease and polishing agent working into the surface

4. Preservation

Avoid the following ingredients:

Metal soaps
Alkali soaps
Sulphurated oils
Chlorinated substances
Natural oils (rapeseed ester)
Ester oils
Waxes and fats with a melting point > 50°C
Zinc
Silicones

Recommended ingredients:

Mineral oils, not pre-emulsified
Paraffin oils
Fatty alcohols

Other Notes:

Sufficient mechanical protection (transport damage)
Intact packaging (reuse for return)
Avoid corrugated cardboard packaging