This practice includes industrial-type flail mowers designed for operation with tractors having at least 20 hp (15 kw) and used for cutting grass adjacent to highways or similar types of grass and growth control. Purpose: This SAE Recommended practice is intended to be used as a guide for manufacturers and users of industrial-type flail mowers to improve the degree of personal safety for operators and others during normal operation and servicing. Inclusion of this practice in state@ federal@ or any laws or regulations where flexibility of revision is lacking is discouraged.