a clamp to lock the end of the tubing inside the die  block,  and  a  yoke  with  a  compressor  screw and cone that slips over the die block and forms the  45-degree  flare  on  the  end  of  the  tube.  The screw has a T-handle. A double flaring tube has adaptors that turn in the edge of the tube before a  regular  45-degree  double  flare  is  made. To  use  the  single  flaring  tool,  first  check  to see  that  the  end  of  the  tubing  has  been  cut  off squarely  and  has  had  the  burrs  removed  from both  inside  and  outside.  Slip  the  flare  nut  onto the  tube  before  you  make  the  flare.  Then,  open the  die  block.  Insert  the  end  of  the  tubing  into the  hole  corresponding  to  the  OD  of  the  tubing so that the end protrudes slightly above the top face of the die blocks. The amount by which the tubing  extends  above  the  blocks  determines  the finished diameter of the flare. The flare must be large enough to seat properly against the fitting, but small enough that the threads of the flare nut will slide over it. Close the die block and secure the tool with the wing nut. Use the handle of the yoke to tighten the wing nut. Then place the yoke over the end of the tubing and tighten the handle to force the cone into the end of the tubing. The completed  flare  should  be  slightly  visible  above the  face  of  the  die  blocks. FLEXIBLE HOSE Shock-resistant, flexible hose assemblies are required  to  absorb  the  movements  of  mounted equipment  under  both  normal  operating  condi- tions  and  extreme  conditions.  They  are  also used  for  their  noise-attenuating  properties  and to  connect  moving  parts  of  certain  equipment. The  two  basic  hose  types  are  synthetic  rubber and  polytetrafluoroethylene  (PTFE),  such  as Du   Pont’s   Teflon^®fluorocarbon resin. Figure 5-9.—Synthetic rubber hoses. pressure  ranges:  low,  medium,  and  high.  The outer cover is designed to withstand external abuse and  contains  identification  markings. Synthetic  rubber  hoses  with  rubber  covers  are identified  with  the  military  specification  number, the size by dash number, the quarter and year of cure  or  manufacture,  and  the  manufacturer’s  code identification   number   or   federal   supply   code number  printed  along  their  layline  (fig.  5-10,  view A). The layline is a legible marking parallel to the longitudinal  axis  of  a  hose  used  in  determining the  straightness  or  lay  of  the  hose. Synthetic rubber hoses with wire braid cover are identified by bands (fig. 5-10, view B) wrapped around the hose ends and at intervals along the length  of  the  hose. Sizing Rubber hoses are designed for specific fluid, temperature, and  pressure  ranges  and  are provided in various specifications. Rubber hoses (fig.  5-9)  consist  of  a  minimum  three  layers;  a seamless synthetic rubber tube reinforced with one or more layers of braided or spiraled cotton, wire, or synthetic fiber; and an outer cover. The inner tube  is  designed  to  withstand  the  attack  of  the fluid  that  passes  through  it.  The  braided  or spiraled layers determine the strength of the hose. The greater the number of these layers, the greater is the pressure rating. Hoses are provided in three 5-8 The size of a flexible hose is identified by the dash  (-)  number,  which  is  the  ID  of  the  hose expressed in 16ths of an inch. For example, the ID of a -64 hose is 4 inches. For a few hose styles this is the nominal and not the true ID. Cure Date Synthetic rubber hoses will deteriorate from aging. A cure date is used to ensure that they do not  deteriorate  beyond  material  and  performance specifications. The cure date is the quarter and year  the  hose  was  manufactured.  For  example,