Crescent Nicholson NICRB10 Round Bastard Cut File 250mm (10in) For filing circular openings or concave surfaces. Slightly tapered towards point. Smooth Cut: approx. 62 teeth per 25mm (Fine). Second Cut: approx. 36 teeth per 25mm (Medium). Bastard Cut: approx. 26 teeth per 25mm (Coarse). Size 250mm (10in) Cut round bastard Single Cut Tanged.