36-37 AIR CORPS
c. When drilling in the lathe, the correct speed usually seems too
fast, due to the fact that the chuck, being so much larger than the
drill, influences the operator's judgment. It is therefore advisable to
refer to a suitable table to obtain the proper speed at which various
materials may be drilled.
d. It is absolutely necessary to have the head and tailstock in
proper alinement during all drilling and reaming operations to pro-
duce a true hole and prevent drill or reamer breakage.
FIGURE 54.-Drilling work held on pad center.
37. Reaming.-a. Reamers are used to finish a number of holes
quickly and accurately to the same diameter. Machine reamers are
frequently used in the lathe and may be held in the same manner as
drills. A typical application of the machine reamers is illustrated in
(1) Machine reamer speeds are approximately one-half that used
(2) When a hole is to be machine reamed, it is drilled or bored
to within 0.005 inch or 0.010 inch of the finished size so that it will
only be necessary for the reamer to remove the tool marks.
United States. Army. Air Corps. Lathes. Washington, D.C.. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc96655/. Accessed November 26, 2015.