Shop Keyed Couplings

Couplings are used to "couple" a pump and motor or engine together. One coupling half slips over the shaft of your engine or motor, one coupling half 

slips over the shaft of your pump, and the flexible insert goes in between to mate the two halves together. The higher the series of your coupling, the more robust the coupling. The close machining tolerances of these couplings assures vibration-free operation and easy, accurate alignment without need for special tools.

Keyed Flexible Insert Coupling Halves

Magnaloy Coupling Hub part numbers may be specified using the following format: Start with letter “M” designating Magnaloy, followed by 3 digit 

Model Code (100, 200, etc.), then the specific 5 digit Bore/Key Code. All standard combinations of each series are shown below. 


Series 100 Couplings

Model Number

Bore Size

Key Size

NO BORE

NO KEY

0.375 (3/8")

0.09375 (3/32")

0.4375 (7/16")

0.09375 (3/32")

0.4375 (7/16")

0.125 (1/8")

0.5 (1/2")

0.125 (1/8")

0.5625 (5/16")

0.125 (1/8")

0.625 (5/8")

0.15625 (5/32")

0.625 (5/8")

0.1875 (3/16")

0.6875 (11/16")

0.1875 (3/16")

0.75 (3/4")

0.125 (1/8")

0.75 (3/4")

0.1875 (3/16")

0.875 (7/8")

0.1875 (3/16")

0.875 (7/8")

0.25 (1/4")

1"

0.1875 (3/16")

1"

0.25 (1/4")

1.125 (1-1/8")

0.25 (1/4")


Series 200 Couplings

Model Number

Bore Size

Key Size

NO BORE

NO KEY

0.375 (3/8")

0.09375 (3/32")

0.4375 (7/16")

0.09375 (3/32")

0.4375 (7/16")

0.125 (1/8")

0.5 (1/2")

0.125 (1/8")

0.5625 (5/16")

0.125 (1/8")

0.625 (5/8")

0.15625 (5/32")

0.625 (5/8")

0.1875 (3/16")

0.6875 (11/16")

0.1875 (3/16")

0.75 (3/4")

0.125 (1/8")

0.75 (3/4")

0.1875 (3/16")

0.875 (7/8")

0.1875 (3/16")

0.875 (7/8")

0.25 (1/4")

0.9375 (15/16")

0.25 (1/4")

1"

0.1875 (3/16")

1"

0.25 (1/4")

1.125 (1-1/8")

0.25 (1/4")


Series 300 Couplings

Model Number

Bore Size

Key Size

NO BORE

NO KEY

0.5 (1/2")

0.125 (1/8")

0.5625 (5/16")

0.125 (1/8")

0.625 (5/8")

0.15625 (5/32")

0.625 (5/8")

0.1875 (3/16")

0.6875 (11/16")

0.1875 (3/16")

0.75 (3/4")

0.125 (1/8")

0.75 (3/4")

0.1875 (3/16")

0.875 (7/8")

0.1875 (3/16")

0.875 (7/8")

0.25 (1/4")

0.9375 (15/16")

0.25 (1/4")

1"

0.1875 (3/16")

1"

0.25 (1/4")

1.125 (1-1/8")

0.25 (1/4")

1.1875 (1-3/16")

0.25 (1/4")

1.25 (1-1/4")

0.25 (1/4")

1.25 (1-1/4")

0.3125 (5/16")

1.375 (1-3/8")

0.3125 (5/16")

1.375 (1-3/8")

0.375 (3/8")

1.4375 (1-7/16")

0.375 (3/8")

1.5 (1-1/2")

0.375 (3/8")

1.625 (1-5/8")

0.375 (3/8")


Series 400 Couplings

Model Number

Bore Size

Key Size

NO BORE

NO KEY

0.6875 (11/16")

0.1875 (3/16")

0.75 (3/4")

0.1875 (3/16")

0.875 (7/8")

0.1875 (3/16")

0.875 (7/8")

0.25 (1/4")

1"

0.1875 (3/16")

1"

0.25 (1/4")

1.125 (1-1/8")

0.25 (1/4")

1.25 (1-1/4")

0.25 (1/4")

1.25 (1-1/4")

0.3125 (5/16")

1.375 (1-3/8")

0.3125 (5/16")

1.4375 (1-7/16")

0.375 (3/8")

1.5 (1-1/2")

0.375 (3/8")

1.625 (1-5/8")

0.375 (3/8")

1.75 (1-3/4")

0.375 (3/8")

1.75 (1-3/4")

0.4375 (7/16")

1.875 (1-7/8")

0.5 (1/2")


Series 500 Couplings

Model Number

Bore Size

Key Size

NO BORE

NO KEY

0.75 (3/4")

0.1875 (3/16")

0.875 (7/8")

0.1875 (3/16")

0.875 (7/8")

0.25 (1/4")

1"

0.1875 (3/16")

1"

0.25 (1/4")

1.125 (1-1/8")

0.25 (1/4")

1.25 (1-1/4")

0.25 (1/4")

1.25 (1-1/4")

0.3125 (5/16")

1.375 (1-3/8")

0.3125 (5/16")

1.4375 (1-7/16")

0.375 (3/8")

1.5 (1-1/2")

0.375 (3/8")

1.625 (1-5/8")

0.375 (3/8")

1.75 (1-3/4")

0.375 (3/8")

1.75 (1-3/4")

0.4375 (7/16")

1.875 (1-7/8")

0.5 (1/2")

1.9375 (1-15/16")

0.5 (1/2")

2"

0.5 (1/2")

2.125 (2-1/8")

0.5 (1/2")

2.25 (2-1/4")

0.5 (1/2")

2.375 (2-3/8")

0.625 (5/8")


Series 600 Couplings

Model Number

Bore Size

Key Size

NO BORE

NO KEY

0.75 (3/4")

0.1875 (3/16")

0.875 (7/8")

0.1875 (3/16")

0.875 (7/8")

0.25 (1/4")

1"

0.1875 (3/16")

1"

0.25 (1/4")

1.125 (1-1/8")

0.25 (1/4")

1.25 (1-1/4")

0.25 (1/4")

1.25 (1-1/4")

0.3125 (5/16")

1.375 (1-3/8")

0.3125 (5/16")

1.5 (1-1/2")

0.375 (3/8")

1.625 (1-5/8")

0.375 (3/8")

1.75 (1-3/4")

0.375 (3/8")

1.75 (1-3/4")

0.4375 (7/16")

1.875 (1-7/8")

0.5 (1/2")

1.9375 (1-15/16")

0.5 (1/2")

2"

0.5 (1/2")

2.125 (2-1/8")

0.5 (1/2")

2.25 (2-1/4")

0.5 (1/2")

2.375 (2-3/8")

0.625 (5/8")

2.5 (2-1/2")

0.625 (5/8")

2.625 (2-5/8")

0.625 (5/8")


Series 700 Couplings

Model Number

Bore Size

Key Size

NO BORE

NO KEY

1.25 (1-1/4")

0.3125 (5/16")

1.375 (1-3/8")

0.3125 (5/16")

1.5 (1-1/2")

0.375 (3/8")

1.625 (1-5/8")

0.375 (3/8")

1.75 (1-3/4")

0.375 (3/8")

1.75 (1-3/4")

0.4375 (7/16")

1.875 (1-7/8")

0.5 (1/2")

2"

0.5 (1/2")

2.125 (2-1/8")

0.5 (1/2")

2.25 (2-1/4")

0.5 (1/2")

2.375 (2-3/8")

0.625 (5/8")

2.5 (2-1/2")

0.625 (5/8")

2.625 (2-5/8")

0.625 (5/8")

1.75 (2-3/4")

0.625 (5/8")

2.875 (2-7/8")

0.75 (3/4")


Series 800 Couplings

Model Number

Bore Size

Key Size

NO BORE

NO KEY

1.25 (1-1/4")

0.3125 (5/16")

1.375 (1-3/8")

0.3125 (5/16")

1.5 (1-1/2")

0.375 (3/8")

1.625 (1-5/8")

0.375 (3/8")

1.75 (1-3/4")

0.375 (3/8")

1.75 (1-3/4")

0.4375 (7/16")

1.875 (1-7/8")

0.5 (1/2")

2"

0.5 (1/2")

2.125 (2-1/8")

0.5 (1/2")

2.25 (2-1/4")

0.5 (1/2")

2.375 (2-3/8")

0.625 (5/8")

2.5 (2-1/2")

0.625 (5/8")

2.625 (2-5/8")

0.625 (5/8")

1.75 (2-3/4")

0.625 (5/8")

2.875 (2-7/8")

0.75 (3/4")

3"

0.75 (3/4")

3.25 (3-1/4")

0.75 (3/4")

3.375 (3-3/8")

0.875 (7/8")

3.5 (3-1/2")

0.875 (7/8")

3.625 (3-5/8")

0.875 (7/8")

3.75 (3-3/4")

0.875 (7/8")

3.875 (3-7/8")

1"


Series 900 Couplings

Model Number

Bore Size

Key Size

NO BORE

NO KEY

1.875 (1-7/8")

0.5 (1/2")

2"

0.5 (1/2")

2.125 (2-1/8")

0.5 (1/2")

2.25 (2-1/4")

0.5 (1/2")

2.375 (2-3/8")

0.625 (5/8")

2.5 (2-1/2")

0.625 (5/8")

2.625 (2-5/8")

0.625 (5/8")

1.75 (2-3/4")

0.625 (5/8")

2.875 (2-7/8")

0.75 (3/4")

3"

0.75 (3/4")

3.25 (3-1/4")

0.75 (3/4")

3.375 (3-3/8")

0.875 (7/8")

3.5 (3-1/2")

0.875 (7/8")

3.625 (3-5/8")

0.875 (7/8")

3.75 (3-3/4")

0.875 (7/8")

3.875 (3-7/8")

1"

4.125 (4-1/8")

1"

4.25 (4-1/4")

1"

4.375 (4-3/8")

1"

4.5 (4-1/2")

1"

4.5 (4-1/2")

1.25 (1-1/4")

4.625 (4-5/8")

1.25 (1-1/4")

4.75 (4-3/4")

1.25 (1-1/4")


Coupling Options

Double Set Screws or Clamp options are ideal for improved shaft retention. Just add a 'DSS' or 'C' at the end of the part numbers above to add those options.

Standard Style

Double Set Screw Style

Ideal for improved shaft 

retention of keyed shafts. 

Clamp Style

Ideal for improved shaft 

retention of splined shafts. 


Don't see what you need? Give us a call! Special combinations may be available upon request. 
Want to view all keyed coupling options? Click HERE for our full collection.