RRU Type - Drop-Out Style
    The RRU Type Uniflex coupling is designed for fast, easy installation and removal without disrupting the connected shafts. This is ideal when servicing impellers, bearings and seals. The design consists of two steel hubs fastened with cap screws to a Uniflex double flange coupling (UF Type). The RRU is easily disassembled by simply removing the cap screws and sliding out the UF center spring section.
    This design offers “quick disconnect” for drop out requirements. It can also accommodate a slightly larger shaft diameter than the standard U Type.
    Note: A complete RRU Type coupling is comprised of 2 hubs, 2 hardware kits, and a UF Type center drop out section.
Unit of Measure



N/A RRU100 HUB 7/16 N/KW RSB

Hub Style


Coupling Type

N/A Drop-Out


N/A Steel


N/A Gray/Metallic

Bore Type

N/A Rough Stock Bore


N/A 3.00 lb

Dimensional Data

Bore Size 

N/A 7/16 in


N/A RRU100

Set Screw Thread Size (Dimension T)

N/A No Setscrew

Keyway Size (W x D)

N/A No Keyway

Overall Length

N/A 4.900 in124.46 mm

Min. Bore (Dimensions ID1/ID2)

N/A 0.438 in11.13 mm

Max. Bore (Dimensions ID1/ID2)

N/A 1.375 in34.93 mm

Dimension BC

N/A 2.680 in68.07 mm

Dimension D

N/A 3.120 in79.25 mm

Flange Diameter (Dimension FD)

N/A 3.250 in82.55 mm

Dimension FL

N/A 0.500 in12.70 mm

Dimension FL1

N/A 0.380 in9.65 mm

Dimension HD

N/A 2.310 in58.67 mm

Dimension HL

N/A 1.380 in35.05 mm

Dimension S

N/A 2.180 in55.37 mm

Pin Location (Dimension SL)

N/A 0.440 in

Pin Size

N/A 5/16 in

Cubic inches

N/A 14.57625 in³

Performance Data

Max. Torque

N/A 565.00 in·lb

Max. Speed

N/A 6000 rpm

Max. Recommended End Play

N/A 0.040 in1.02 mm

Max. Parallel Offset

N/A 0.030 in0.76 mm

Max. Angular Offset

N/A 3.00 º

Wind-Up Angle at Max. Torque

N/A 1.03 º

Rated HP at 100 rpm

N/A 0.90 hp

# of Set Screws Required per Hub

N/A 1

Normal Temperature Range

N/A -40 to 240 ºF

Max. Torque

N/A 63.8 N·m565 in·lb

Coupling Design

Coupling Design

N/A Flexible Spring Type Coupling with Exclusive Triple Wound Spring Design
    The Uniflex Coupling is an all steel, single piece coupling that solves a variety of application concerns including: high misalignment, space limitations, high temperature, and exceptionally low backlash/windup. The unique flexing center of the Uniflex consists of three opposingly wound square wire springs for forward or reverse operation. Two steel hubs are then brazed to the steel spring pack to create a durable one-piece flexible coupling.



  • OAL Tolerance + .19 inch.
  • Total backlash is approximately 1/3 of windup at maximum torque – consult Lovejoy Engineering for more information.