TM 1-1500-204-23-9 Table 3-2.  Snap Gauge Tolerances To and Above Including X¹ Y² Z³ 0.029 0.825 0.00004 0.00007 0.00010 0.825 1.510 0.00006 0.00009 0.00012 1.510 2.510 0.00008 0.00012 0.00016 2.510 4.510 0.00010 0.00015 0.00020 4.510 6.510 0.00013 0.00019 0.00025 6.510 9.010 0.00016 0.00024 0.00032 9.010 12.010 0.00020 0.00030 0.00040 1 Precision lapped 2 Lapped 3 Ground or polished (grinding marks may be in evidence) (a) Clamp the snap gauge in a vise or a holder. CAUTION To prevent damage to the gauge from the jaws  of  the  vise,  cover  the  jaws  of  the vise with blocks of wood or sheets of soft metal, such as brass. NOTE This   procedure   describes   adjusting   the GO  dimension  first;  however,  either  the GO   or   the   NO   GO   dimension   may   be adjusted first. (b) As   shown   in   figure   3-65,   turn the  locking  screw  (2)  and  turn  the  adjusting  screws  (1) until the dimension is set (3). NOTE The   desired   dimension   may   be   taken from   a   master   disc,   a   precision   gauge block, or a master plug. (c) Turn  the  other  adjusting  screw until the NO GO dimension is set. (d) Tighten  the  locking  screws  with the master precision piece still in place. (e) Remove   the   master   precision piece. (f) Recheck    the    gauge    to    make sure the dimensions have not changed before using the gauge. LEGEND 1.  ADJUSTING 2.  LOCKINGSCREW 3.  GAUGEFOOT Figure 3-65.  Adjusting the Snap Gauge 3-30