• S flanges are made of high strength cast iron and are bored-to- size for a slip fit on standard shafts.
  • S flanges are easy to install, are readily available from stock in a wide range of popular bore sizes, and are supplied with two set screws at 90°.
  • The S Type coupling consists of two flanges and one sleeve.
Unit of Measure



N/A 11S FLNG 1-1/4 N/KW

Coupling Size

N/A 11S


N/A Coupling Flange


N/A Cast Iron


N/A Gray

Bore Type

N/A Finished Bore

Coupling Type

N/A S-Flex


N/A 20.36 lb

Dimensional Data

Bore Size 

N/A 1 1/4 in

Thread (Dimension T)

N/A 1/2-13

Keyway Size (W x D)

N/A No Keyway

Outside Diameter

N/A 9.625 in244.48 mm

Max. Bore (Dimension ID)

N/A 3.375 in

Dimension FL

N/A 1.500 in38.10 mm

Dimension HD

N/A 5.250 in133.35 mm

Dimension L

N/A 3.440 in87.38 mm

Dimension P

N/A 1.130 in28.70 mm

Dimension SL

N/A 0.560 in14.22 mm

Cubic inches

N/A 318.68375 in³

Performance Data

Nominal Torque (with EPDM Sleeve)

N/A 4530 in·lb

Max. Speed

N/A 3600.00 rpm

Torsional Stiffness

N/A 17300.00 in·lb/rad

Rated HP at 100 rpm

N/A 7.20 hp

Rated HP at 1,200 rpm

N/A 86.00 hp

Rated HP at 1,800 rpm

N/A 129.00 hp

Rated HP at 3,600 rpm

N/A 259.00 hp



  • All standard finished bore keyway flanges have 2 set screws at 90°.
  • Sizes 13, 14 and 16 RSB flanges are suitable for reboring and have two set screws at 90°.
  • Sizes 5-12 RSB flanges have no set screws.
  • Metric Bore / Keyway per DIN specifications.
  • Spacing between shafts should be greater than 1/8 inch and less than OAL minus the sum of the two bore dimensions.