Spur Gears - Norfolk Bearings and Supply Company, Inc.

BEAR-N-BRONZ is Boston Gear’s general purpose cast, solid
bronze bearing material. It is a high grade, leaded-tin bronze,
having good hardness, strength, wear-resistance, and
exceptional anti-friction qualities. It is particularly suited for
moderate to heavy loads at normal to relatively high speeds.
Quality
BEAR-N-BRONZ is chemically and metallurgically tested to
assure conformance to specifications. All parts are rigidly
inspected to assure freedom from porosity and conformance
to dimensional tolerances.
Adaptability
BEAR-N-BRONZ bearings are completely machined to close
tolerances permitting wider housing-bore tol er ances. BEAR-N-
BRONZ bars are machined all over.
Composition
(%)
Avg.
Avg.
Yield
Tensile Strength
Strength 0.2%
(Lbs. Per Offset
Sq. In.) (Lbs. Per
Sq. In.)
BEAR-N-BRONZE 660 Cast Bronze Bearings
Elonga- Brinnell
tion in Hardness
Two Inch (500 Kg
(%) Load)
Copper (Cu) 83 35,000 20,000 15 60
Tin (Sn) 7 Bear-N-Bronz conforms to SAE CA932 (660)
Lead (Pb) 7 and ASTM B584-78 (alloy C93200)
Zinc (Zn) 3 specifications.
Special Compositions
In addition to our standard BEAR-N-BRONZ (SAE CA 932)
material, many special compositions can be furnished on a madeto-order
basis.
The Chemical compositions and physical properties of some
of the more popular are listed.
206 Copper (Cu) 88
Leaded CA927 Tin (Sn) 1040,00020,000 25 70
Gun Metal Lead (Pb) 2
210 Copper (Cu) 88
Gun CA905 Tin (Sn) 10 45,000 22,000 25 65
Metal Zinc (Zn) 2
305 Copper (Cu) 80
Phosphor CA937 Tin (Sn) 10 35,000 18,000 20 63
Bronze Lead (Pb) 10
319 Copper (Cu) 78
Semi-Plastic CA938 Tin (Sn) 7 30,000 17,000 15 55
Bronze Lead (Pb) 15
Selection
In general, sleeve bearings should be selected with a length of
one to two times the shaft diameter and an O.D. approximately
25% larger than the shaft diameter.
A general guide to determination of limiting load and velocity
values for sleeve bearings has been estab lished by the use of
PV calculations. PV represents Pressure x Velocity, for
example 100 psi x 20 fpm yields a PV of 2000.
Maximum PV value for BEAR-N-BRONZ bearings: 75,000.
For complete selection and application information, see
Engineering Section, Pages 174-182.
P-1930-BG 04/10 Boston Gear 800-825-6544 145
Grade
Equivalent
S.A.E. Number
Composition
(%)
Average
Yield Strength
0.2% Offset
(Lbs. Per Sq. In.)
Average
Tensile Strength
(Lbs. Per Sq. In.)
Elongation in
Two Inch (%)
Brinnell
Hardness
(500 Kg Load)
F