Sherline Mill and Lathe Specifications
manufacturer. The base and several other parts were cast to match this angle and it 
was not economically feasible at the time to change it to an easier-to-
manufacture 60 
degrees. The original 55-degree angle was determined by a reference to Machinery's 
Handbook, Vol. 17 as the ideal angle to cut a dovetail. When we took over 
production, a fixture was produced in-house to duplicate the existing angle which 
had changed slightly from the original 55° to an actual 55.5°. This fixture became 
the "standard", and every machine built since the early 1970's has been measured 
against this same fixture. The older brass beds and the current steel beds as well as 
the parts that fit them are all ground to this same angle. 
ALLOWABLE TOLERANCES 
Spindle Runout (at spindle nose), Maximum allowable 
(Most are within .0002-.0003") 
0.0005" 
Spindle End Play (adjustable with preload nut), Factory 
Settings 
with 2800 RPM Pulleys: 
0.0002" 
with 10,000 RPM 
Pulleys: 0.0003" 
Self-Centering 3-jaw and 4-jaw chuck runout  0.003" or less 
Leadscrew thread pitch accuracy 
±0.001" per inch of 
travel 
COLLETS 
Sherline WW Collet body diameter  0.312" to 0.313" 
8 mm WW collets (by others), body diameter  0.314" to 0.315" 
WW and 8 mm collet thread  .275-40 
HEADSTOCK BEARINGS 
Designation/stock number (ZZ refers to "double 
shielded") 
6004ZZ 
Size of bore  20 mm (0.7874") 
Tolerance of bore  0.0004" 
Outside Diameter  42 mm (1.6535") 
Tolerance of OD  0.0005" 
Width  12 mm (0.4724") 
Bearings  9 balls, 1/4" dia. 






