This standard establishes a uniform relationship
between shaft size and key size for parallel
and taper keys retaining similar basic sizing as
found in the withdrawn B17.1-1943 standard.
This standard covers the size, type and tolerances
of parallel and taper keys and keyseats,
and their relationship to shaft diameters and bore
diameters. The sizes and tolerances contained
in this standard are intended for single key applications
only.
Key strength and steel analysis entering into
the makeup of stock for keys is not within the
scope of this standard. Shaft diameters are listed
for identification of various key sizes and are not
intended to establish shaft dimensions, tolerances
or selections,
This standard recognizes that there are two
classes of stock for parallel keys presently used
by industry. One is a broad negative toleranced
bar stockand the other is a close plus toleranced
keystock. Each is combined with appropriate keyseat
tolerances to establish assemblies, respectively,
designated as Classes 1 and 2.
Taper keys are established for Class -2 assembly
only.