Object and Scope
This standard establishes (1) the American practice for the
construction of spindle noses for horizontal boring machines by
showing a number of types of such construction, (2) the important
dimensions for self-holding and steep machine tapers as well as
drive keys, draw bolts, drift and keeper key slots, bolt circles
for face mounting of milling cutters, etc., (3) the corresponding
dimensions for the taper shanks for construction of tools (boring
bars, arbors, etc.) to fit the spindle nose tapers.
The purpose of such construction is to provide an accurately
machined socket to locate tools with means to positively hold them
in position in the spindle as will as with means to positively
drive the tools.
In many of the tables, reference is made to another standard on
machine tapers, American National Standard Machine Tapers
B5.10-1963 (R1972), in which basic dimensions and tolerances for
tapers used in this standard are tabulated. Other tolerances
pertaining only to horizontal boring machine spindle noses are
given in tables of this standard. The object is to establish data
for tapers that will be universally used. Wherever keys are used as
a driving means, they are detailed completely with the purpose that
these perishable parts can be made to fit all spindles complying
with the standard.
Because of the lack of such a standard as this, many spindle
nose constructions have appeared and are in use. This standard
limits the accepted number of constructions; and for those other
constructions that have wide use, an appendix is supplied so that
dimensions and tolerances can be applied.