TM 1-1500-204-23-4 e. Wire  Stripping.    Insulation  must  be  be  stripped from   connecting   ends   to   expose   the   bare   conductor before wire can be assembled to connectors, terminals, or    splices.        The    following    general    precautions    are recommended when stripping any type of wire: · When using any type of wire stripper, hold the wire so that it is perpendicular to cutting blades. · Adjust automatic stripping tools carefully; follow the manufacturer's instructions to avoid nicking, cutting, or  otherwise  damaging  strands.    This  is  especially important  for  aluminum  wires  and  for  copper  wires smaller  than  No.    10.    Examine  stripped  wires  for damage.  Cut off and restrip (if length is sufficient), or  reject  and  replace  any  wires  having  more  than the  allowable  number  of  nicked  or  broken  strands listed in the manufacturer's instructions. · Make  sure  insulation  is  clean-cut  with  no  frayed  or ragged edges.  Trim if necessary. · Make  sure  all  insulation  is  removed  from  stripped area.      Some   types   of   wires   are   supplied   with   a transparent layer of insulation between the conductor   and   the   primary   insulation.      If   this   is present, remove it. · When  using  hand-plier  strippers  to  remove  lengths of  insulation  longer  than  3/4  in.    ,  it  is  easier  to accomplish in two or more operations. · Re-twist  copper  strands  by  hand  or  with  pliers,  if necessary,  to  restore  natural  lay  and  tightness  of strands. (1) Aluminum  wire.    Aluminum  wire  must  be stripped with extreme care, since individual strands will break very easily after being nicked. (2) Copper wire.  Copper wire can be stripped in   a   number   of   ways,   depending   on   the   size   and insulation.  Table 3-1 lists some types of stripping tools recommended    for    various    wire    sizes    and    types    of insulation. f. Marking of Wires with Marking Machine. Marking machines, as shown in figures 3-2 and 3-3, are used  to  stamp  the  identification  code.    For  stamping  a large   number   of   long   wires,   use   an   automatic-wire marking machine.  In machines of this type as shown in figure  3-2,  wire  sizes  No.    26  through  No.    14  are  fed through  and  stamped  automatically.    Wires  larger  than No.        14    are    fed    through    by    hand,    but    stamped automatically.  For short wires, on repair or maintenance work,  a  hand  operated  wire  marking  machine  is  more convenient  and  economical  as  shown  in  figure  3-3.    In this type of machine, the desired amount of wire is fed through by hand, and stamped by operating the handle for  each  marking.    Wire  guide  holders  in  sizes  to  fit wires, and slot holders to hold appropriate size type, are furnished to fit the machines.  Type is supplied in three sizes to mark wire No.  26 through No.  0000, as shown in  table  3-2.    Marking  foil  is  available  in  black  or  white (and other colors if needed for special applications). NOTE Store  foils  at  approximately  70 °F and 60 percent relative humidity. g. Terminals and Terminal Blocks.  When installing terminals     and     terminal     blocks,     inspect     using     the following procedures: (1) Check   that   insulating   tubing   is   placed over  terminals  (except  pre-insulated  types)  to  provide electrical   protection   and   mechanical   support,   and   is secured   to   prevent   slippage   of   the   tubing   from   the terminal. Table 3-1.  Copper Wire Strippers Stripper Wire size Insulations Hot-blade No.  26 - No.  4 All except asbestos Rotary, Electric No.  26 - No.  4 All Bench No.  20 - No.  6 All Hand Pliers No.  26 - No.  8 All Knife No.  2 - No.  0000 All 3-4