TM 1-1500-204-23-9 Figure 8-15.  Concentric Torque Wrench Attachments (a)  Extending lever length.  Figure 8-16 shows an attachment   that   adds   to   the   lever   length   with   the applicable    formula    for    obtaining    the    correct    torque reading.  The formula is as follows: TA x L TW= L+A where: TA =  Actual torque applied to fastener TW = Indicated torque value on torque wrench L = Lever length A = Attachment length For  example,  if  the  length  of  the  torque  wrench  is  10 inches, the length of the attachment Is 4 inches, and the desired  torque  to  be  applied  is  300  inch-pounds,  the formula would be completed as follows: TA x L TW= L+A 300 x 10 TW= 10+4 3000 TW= 14 TW = 214 inch-pounds Therefore,  the  torque  wrench  must  indicate  214  inch- pounds in order for the desired torque of 300 pounds to be obtained on the fastener. (b)  Shortening lever length.  In the previous case of   added   lever   length,   the   indicated   torque   value   is smaller   than   the   actual   torque   value.      Attachments, when used as shown in figure 8-17, shorten the effective lever length.  In these instances, the attachment length A  is  subtracted  in  the  formula  and  the  indicated  torque value is greater than the actual torque value. (c)  Importance of proper technique.  When using these formulas, the lever length L is a critical factor.  On a  flexible  beam-type  wrench  with  a  pivoted  grip,  this dimension   is   fixed,   and   the   pivot   point   of   the   grip determines  the  point  of  force  application  and  therefore the length of the lever.  On the rigid frame and audible- indicating torque wrenches, the point of force application must be in the center of the grip as shown in figure 8-18. In figure 8-18, using the 10-inch lever length, 107 inch- pounds of torque, as read on the torque wrench, results in 150-pounds of torque on the fastener when the force is applied correctly to the center of the grip.  If the force were applied to the torque wrench at the tip end or the root  of  the  grip,  as  shown  in  figure  8-19,  at  the  same 107   inch-pounds   reading,   the   torque   applied   to   the fastener  would  be  142.6  inch-pounds  and  160.5  inch- pounds, respectively. (3)  Angle attachments.  Attachments will not always extend  straight  from  the  end  of  the  torque  wrench.    In instances  where  the  centerline  of  the  adapter  is  not  in line  with  the  centerline  of  the  torque  wrench,  as  shown in figure 8-20, the length of the adapter is not used.  The effective  length  used  to  calculate  the  torque  reading  is the distance A in figure 8-20. 8-6.      Care   of   Torque   Tools.      A   torque   tool   is   a precision  measuring  tool  and,  when  handled  and  used with reasonable care, will remain accurate and serviceable for a considerable period of time.  Observe the following practices for the care and upkeep of torque tools: a.    Never  toss  a  torque  tool  carelessly  among  other tools.  Stow it in a clean, dry place where it will not be subjected to shock or damage. b.    On  audible-indicating  torque  wrenches,  return  the micrometer-type  barrel  to  lowest  setting  after  each  use and before returning to storage. Change 1 8-7