---+---------+---------+---------+---------+
| | High Limit | -0.0010 | -0.0012 | -0.0017 | -0.0020 | -0.0025 |
| X | Low Limit | -0.0020 | -0.0027 | -0.0035 | -0.0042 | -0.0050 |
| | Tolerance | 0.0010 | 0.0015 | 0.0018 | 0.0022 | 0.0025 |
| | High Limit | -0.0007 | -0.0010 | -0.0012 | -0.0015 | -0.0020 |
| Y | Low Limit | -0.0012 | -0.0020 | -0.0025 | -0.0030 | -0.0035 |
| | Tolerance | 0.0005 | 0.0010 | 0.0013 | 0.0015 | 0.0015 |
| | High Limit | -0.0005 | -0.0007 | -0.0007 | -0.0010 | -0.0010 |
| Z | Low Limit | -0.0007 | -0.0012 | -0.0015 | -0.0020 | -0.0022 |
| | Tolerance | 0.0002 | 0.0005 | 0.0008 | 0.0010 | 0.0012 |
+-----+------------+---------+---------+---------+---------+---------+

[1] Tolerance is provided for holes, which ordinary standard reamers can
produce, in two grades, Classes A and B, the selection of which is a
question for the user's decision and dependent upon the quality of the
work required; some prefer to use Class A as working limits and Class B
as inspection limits.

[2] Running fits, which are the most commonly required, are divided into
three grades: Class X for engine and other work where easy fits are
wanted; Class Y for high speeds and good average machine work; Class Z
for fine tool work.

=Pressure for Forced Fits.=--The pressure required for assembling
cylindrical parts depends not only upon the allowance for the fit, but
also upon the area of the fitted surfaces, the pressure increasing in
proportion to the distance that the inner member is forced in. The
approximate ultimate pressure in pounds can be determined by the use of
the following formula in conjunction with the accompanying table of
"Pressure Factors."

=Pressure Factors=

+-----+-----++-----+-----++-----+-----++------+------++------+------+
|Diam-|Pres-||Diam-|Pres-||Diam-|Pres-||Diam- |Pres- ||Diam- |Pres- |
|eter,|sure ||eter,|sure ||eter,|sure ||eter, |sure ||eter, |sure |
|In- |Fac- ||In- |Fac- ||In- |Fac- ||In- |Fac- ||In- |Fac- |
|ches | tor ||ches | tor ||ches | tor ||ches |tor ||ches |tor |
+-----+-----++-----+-----++-----+-----++------+------++------+------+
|1 | 500 ||3-1/2| 132 ||6 | 75 || 9 | 48.7 ||14 | 30.5 |
|1-1/4| 395 ||3-3/4| 123 ||6-1/4| 72 || 9-1/2| 46.0 ||14-1/2| 29.4 |
|1-1/2| 325 ||4 | 115 ||6-1/2| 69 ||10 | 43.5 ||15 | 28.3 |
|1-3/4| 276 ||4-1/4| 108 ||6-3/4| 66