... +- 0,5 mm in the width and +-0,5 mm (only in plus) birch slat1. Radius of curvature: 5000mm 2. Tolerances: +-1 ... ,5 mm in the width and +-0,5 mm (only in plus) in the thickness 3. Class of formaldehyde emission: E1 4 ... use too hot material - after such quick production the effect of"propeller blade" appears (slats are warped, a little bit "twisted")11 ...