Modified Stock Gearing - Boston Gear

Shaft Couplings
BF Series Bost-Flex ®
Spider Ring (3-Jaw) Type
ECONOMICAL 3-JAW COUPLING
SPIDER RING URETHANE INSERT absorbs shock
and vibration. Provides through opening for close
coupling of shafts.
BORE SIZES FROM 3/8” TO 1-1/4”
COMPLETE WITH KEYWAY AND SETSCREW.
OVERALL
LENGTH
KEYWAY
STANDARD TOLERANCES
Dimensions
Tolerance
Bore All +.001 – .000
O.D.
BORE
HUB
DIA.
Reference Pages
Alignment—312
E
F
SETSCREW
Keyways and Setscrews—313
E
ALL DIMENSIONS IN INCHES
ORDER BY CATALOG NUMBER OR ITEM CODE
Includes two coupling halves and one coupling insert
Replacement
Coupling
Bore
Approx.
Coupling
Hub Overall Assembly
Insert
Size
Diameter
O.D.
E F
Weight
Length
Clearance
Catalog Item Item
A B (Oz.)
Number Code Code
3/8 BF7 3/8–3/8 11730
BF7 3/8 1/2 7/8 1-7/32 1-5/16 1/2 5/16 1-5/8 2 BF7 3/8–1/2 11734 11722
1/2 1/2 BF7 1/2–1/2 11732
1/2 BF10 1/2–1/2 11736
1/2 5/8 BF10 1/2–5/8 11742
BF10 3/4 1-1/4 1-19/32 1-15/16 3/4 7/16 2-3/8 6.5 BF10 1/2–3/4 11744 11724
5/8 5/8 BF10 5/8–5/8 11738
3/4 BF10 5/8–3/4 11746
3/4 3/4 BF10 3/4–3/4 11740
3/4 BF13 3/4–3/4 11748
3/4 7/8 BF13 3/4–7/8 11754
BF13 1 1-5/8 1-31/32 2-7/16 15/16 9/16 3 14 BF13 3/4–1 11756 11726
7/8 7/8 BF13 7/8–7/8 11750
1 BF13 7/8–1 11758
1 1 BF13 1–1 11752
1 BF18 1–1 11760
1 1-1/8 BF18 1–1-1/8 11766
BF18
1-1/4
BF18 1–1-1/4 11768
2-1/4 2-23/32 2-15/16 1-1/8 11/16 3-5/8 37
1-1/8 1-1/8 BF18 1-1/8–1-18 11762
11728
1-1/4 BF18 1-1/8–1-1/4 11770
1-1/4 1-1/4 BF18 1-1/4–1-1/4 11764
Selection Procedure
For Service Factors and Procedures,
refer to FC Couplings (Page 100).
HORSEPOWER AND TORQUE RATINGS
Size
Revolutions per Minute
Max Torque
100 300 690 870 1150 1750 3450 (Lb. Ins.)
BF 7 .044 .13 .31 .39 .51 .78 1.5 28
BF 10 .11 .34 .78 1.00 1.30 2.00 3.9 72
BF13 .25 .76 1.70 2.20 2.90 4.40 8.8 160
BF 18 .48 1.40 3.30 4.10 5.50 8.30 16.4 300
102 Boston Gear 800-825-6544 P-1930-BG 04/10