Machinery's Handbook, 31st Edition
2442
Plain Bearing Materials Table 5a. Copper- and Iron-Base Sintered Bearings (Oil Impregnated) ASTM B438-17, ASTM B439-18, and Appendices Chemical Requirements
Percentage Composition
Copper-Base Bearings
Iron-Base Bearings
Grade 1
Grade 2
Grades
Alloying Elements a
Class A Class B Class A Class B 87.5-99.5 87.5-90.5 87.5-90.5 87.5-90.5 9.5-10.5 9.5-10.5 9.5-10.5 9.5-10.5
1
2
3
4
Cu Sn Pb Fe
… … 7.0-11.0 18.0-22.0 … … … … … … … … … … … …
Graphite 0.1 max. 1.75 max. 0.1 max. 1.75 max.
… … 2.0-4.0 2.0-4.0
1.0 max. 96.25 min. 95.9 min. Balance b
Balance b
1.0 max.
1.0 max.
1.0 max.
Comb. C c Si, max. Al, max.
… … … … 0.25 max. 0.25-0.60
… … … … … …
… … … … 0.3 … … … … 0.2
0.3 0.2
Others 3.0 max. a Abbreviations used for the alloying elements are as follows: Cu, copper; Fe, iron; Sn, tin; Pb, lead; Zn, zinc; Ni, nickel; Sb, antimony; Si, silicon; Al, aluminum; and C, carbon. b Total of iron plus copper shall be 97 percent, minimum. c Combined carbon (on basis of iron only) may be a metallographic estimate of the carbon in the iron. Permissible Loads Copper-Base Bearings Iron-Base Bearings 0.5 max. 0.5 max. 1.0 max. 1.0 max. 3.0 max. 3.0 max. 3.0 max.
Grades 1 & 2
Types 3 & 4
Grades 1 & 2
Grades 3 & 4
Type 1
Type 2
Shaft Velocity, fpm Slow and intermittent
Max. Load, psi
Shaft Velocity, fpm Slow and intermittent
Max. Load, psi
3200 2000 500 365 280
4000 2000 500 325 250
4000 2000 550 365 280
3600 1800 450 300 225
8000 3000 700 400 300
25
25
50 to 100
50 to 100
Over 100 to 150 Over 150 to 200
Over 100 to 150 Over 150 to 200
a
a
a
a
Over 200
Over 200
a For shaft velocities over 200 fpm, the permissible loads may be calculated as follows: P = 50,000/ V ; where P = safe load, psi of projected area; and V = shaft velocity, fpm. With a shaft veloc- ity of less than 50 fpm and a permissible load greater than 1,000 psi, an extreme pressure lubricant should be used; with heat dissipation and removal techniques, higher PV ratings can be obtained. Clearances Press-Fit Clearances Running Clearances a Copper- and Iron-Base Copper-Base Iron-Base Bearing OD Min. Max. Shaft Size Min. Clearance Shaft Size Min. Clearance Up to 0.760 0.001 0.003 Up to 0.250 0.0003 Up to 0.760 0.0008 0.761-1.510 0.0015 0.004 0.250-0.760 0.0005 0.761-1.510 0.0013 1.511-2.510 0.002 0.005 0.760-1.510 0.0010 1.511-2.510 0.0018 2.511-3.010 0.002 0.006 1.510-2.510 0.0015 Over 2.510 0.0023 Over 3.010 0.002 0.007 Over 2.510 0.0020 a Only minimum recommended clearances are listed. It is assumed that ground steel shafting will be used and that all bearings will be oil-impregnated.
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