• 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 5S FLNG 1/2 N/KW

Coupling Size

N/A 5S


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 1.37 lb

Dimensional Data

Bore Size 

N/A 1/2 in

Thread (Dimension T)

N/A 1/4-20

Keyway Size (W x D)

N/A No Keyway

Outside Diameter

N/A 3.250 in82.55 mm

Max. Bore (Dimension ID)

N/A 1.188 in

Dimension FL

N/A 0.590 in14.99 mm

Dimension HD

N/A 1.880 in47.75 mm

Dimension L

N/A 1.34 in34.04 mm

Dimension P

N/A 0.450 in11.43 mm

Dimension SL

N/A 0.290 in7.37 mm

Cubic inches

N/A 14.15375 in³

Performance Data

Nominal Torque (with EPDM Sleeve)

N/A 240 in·lb

Max. Speed

N/A 7600.00 rpm

Torsional Stiffness

N/A 916.00 in·lb/rad

Rated HP at 100 rpm

N/A 0.40 hp

Rated HP at 1,200 rpm

N/A 4.60 hp

Rated HP at 1,800 rpm

N/A 6.90 hp

Rated HP at 3,600 rpm

N/A 13.70 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.