TM 1-1500-204-23-9 Figure 4-44.  Flat-Nose Pliers (5) Round-nose pliers.  The round-nose pliers are used to crimp flanges on sheet metal in the process of  shrinking,  and  for  making  loops  in  soft  wire.    It  has smooth,  round  jaws,  a  fixed  pivot,  and  curved  handles which may have insulated sleeves.  It is shown in figure 4-45. (6) Crimping   pliers.      Crimping   pliers   have practically   the   same   design   as   ordinary   round-nose pliers.    Because  a  crimp  in  sheet  metal  is  made  by twisting  rather  than  clamping,  they  are  constructed  of heavier  material  to  withstand  heavy  side  loads  induced by the twisting motion. (7) Water  pump  pliers.    Water  pump  pliers, sometimes  referred  to  as  channel  lock  pliers,  are  used for  their  powerful  grip  and  ability  to  adjust  to  several different  sizes.    As  figure  4-46  shows,  there  are  two adjustment methods used with this type of pliers. (8) Vise-grip  pliers.    Vise-grip  pliers  have  a clamping  action  which  allows  them  to  be  clamped  onto an object.  They will stay there and free the other hand for  other  work.    These  pliers,  shown  in  figure  4-47,  are sometimes  made  with  a  clamp-type  jaw  which  allows them  to  be  used  for  clamping  sheet  metal.    The  vise- grip   pliers   can   be   adjusted   by   turning   the   knurled adjustment   screw   until   the   desired   jaw   dimension   is reached. NOTE Vise-grip  pliers  should  be  used  with  care since    the    teeth    in    the    jaws    tend    to damage   the   object   on   which   they   are clamped.  Do not use them on nuts, bolts, tube  fittings,  or  other  objects  which  must be reused. b. Use.    Pliers  come  in  various  sizes  and  should be selected according to the job being performed.  They should   never   be   used   as   a   substitute   for   a   wrench, because   this   practice   batters   nut   and   jaw   serrations unnecessarily.      Although   there   are   several   uses   for pliers, they are not an all-purpose tool and should not be used as a pry bar or for hammering. Figure 4-45.  Round-Nose Pliers c. Repair.    Generally  speaking,  repair  of  pliers  is limited  to  grinding  or  filing  cutting  or  holding  surfaces. Further   repair   of   pliers   is   usually   impractical   when compared with the replacement cost. (1) Grinding.  It is possible to grind or sharpen some types of side cutting pliers.  However, they should be  examined  closely  to  see  if  they  still  close  properly after the material is ground away from the cutting edges. Do not attempt to grind pliers not designed to be ground. Grind cutting edges so that ground bevel is approximately at right angles to inside machined bevel. Grind sparingly, and remove the same amount of stock from both jaws.  Cool often in water to preserve temper. (2) Renewing serrations.  Jaw face serrations may be renewed by placing pliers in a vise and renewing serrations with a 4-or 5-inch, three-cornered file. d. Care.    Observe  the  following  practices  for  the care and upkeep of pliers: (1) Remove  dirt  and  grease  with  a  clean  rag and apply a light coat of oil after each use. (2) Store pliers in a tool box or hang on racks when not in use. (3) Do not remove insulation on handles or oil handles which are insulated. (4) Do    not    use    pliers    for    prying    or    for removing nuts or bolts. (5) Replace    all    pliers    which    have    broken jaws, handles, or cutting edges. 4-6.    Awls.    Awls  are  used  in  aircraft  maintenance  to align holes, as in the installation of a deicer boot, and to place  scribe  marks  on  metal  and  plastic  surfaces.    A typical awl is shown in figure 4-48. 4-15