TM 1-1500-204-23-8 2-2           Change 1 (5) Safety devices, such as guards, interlocks, automatic releases, and stops, shall always be kept in operating condition. (6) Ensure that all unauthorized personnel are clear of area before opening valves or energizing electri- cal circuits for starting machinery. (7) Suitable mechanical guards, such as enclo- sures or barricades, shall be permanently installed on all machinery not already equipped with such to eliminate danger of injury from moving parts. (8) Machinery shall not be adjusted, repaired, oiled, or cleaned while machine is in operation or power is on. (9) Personnel operating machinery shall wear protective clothing as prescribed. A protective face shield or  goggles  shall  be  worn  when  operating  a  grinder regardless of whether grinder is equipped with attached shields. (10) Jewelry shall not be worn while performing any maintenance. d.  Fire Safety.  A constant vigilance must be main- tained   to   seek   out   fire   hazards.   Fire   hazards   are constantly present in the shop where sparks, friction, or careless  handling  can  cause  an  explosion  that  may destroy equipment or buildings, and injure or kill person- nel. Refer to AR 385-10, The Army Safety Program and the  Occupational  Safety  and  Health  Act  of  1971.  The following fire safety practices shall be observed: (1) NO  SMOKING  signs  shall  be  placed  in areas where smoking could create a fire hazard. (2) Personnel shall be trained in the use, knowl- edge, and location of shop fire fighting equipment. (3) Each shop shall be equipped with  fire extin- guishers suited for type fire most likely to occur. (4) Use correct fire extinguisher  for class of fire as follows: Class A fire (wood, paper, trash, etc). Use  water or soda-acid fire extinguisher. Class B fire (oil, paint, fuel, grease, etc). Use  dry chemical or CO₂ if available. Class C fire (electrical equipment). Use  dry chemical or CO₂ if available. Class D fire (combustible metals) magnesium, titanium, zirconium, sodium, lithium, and potas- sium. Use dry powder type fire extinguisher. (5) Oily  waste,  rags,  and  similar  combustible materials shall be discarded in self-closing metal con- tainers which shall be emptied daily. (6) Flammable materials shall not be stored in the shop. (7) Use only approved  cleaning solvents. 2-3.  Machine Safety Precautions.    The information in the following paragraphs does not give specific proce- dures for operation of various type machinery found in the machine shop, but does include safety measures and general practices involved in the use of machines. For information on operation and service of specific machin- ery, refer to the applicable operation and service instruc- tions manual. a.  Drilling    Machines.  Use    drilling    machines    for reaming, boring, facing, and similar operations. The fol- lowing safety precautions shall be followed when using drilling machines: Clamp work securely so that work will not move. Do not permit spindle (rotating shaft with chuck attached) to feed beyond its limit of travel when drilling. Use a bit with the flute ground slightly flat when drilling brass or bronze. Stop machine prior to attempting to adjust work that has become jammed. b.  Grinding  Machines.  Use  grinding  machines  for sharpening  tools,  dressing  metal,  and  other  functions requiring removal of small amounts of  metal. The follow- ing  safety  precautions  shall  be  followed  when  using grinding machines: Wear goggles regardless of whether or not machine is equipped with a transparent shield.