MM Series


  • High torque capacity yet compact direct mounting design
  • Suitable for backstopping applications
  • DM clutches drive directly onto the shaft, without an inner race, resulting in compact design.
  • The clutch is suitable for use in gear units where the oil provides lubrication


  • Conveyor Drives
  • Foundry equipment drives
  • Steel works
  • Textile machinery
  • Packaging machinery
  • Water treatment

Overrunning - Indexing - Backstopping
Direct mounting sprag clutch without bearings

Sprag Clutch Freewheels

DM series direct mounting sprag clutches are specifically designed for use as backstops in applications where
compact dimensions are required. The clutch is designed to fit in a housing with the shaft as the inner race.

This type is particularly suitable for use in gear units and similar equipment where good concentricity
between shaft and housing is ensured. For all applications it is essential that shafts conform of the following


Shaft diameter to tolerances shown in table for dimension 'B'


To an effective depth of 1.27 / 1.52mm (0.050'' / 0.060'') after grinding


Surface HV30 650 to 750. Core HV30 250 to 400


Surface finish 13 to 20 micro-inches CLA


Not to exceed 0.0003'' per inch


Shaft to be supported in bearings such that shaft and housing are concentric within 0.05mm (0.002") TIR

Diametral Clearance

Within housing to be 0.025 to 0.076mm (0.001" to 0.003")

Renold Clutches and  Couplings Logo  DM Series Sprag Clutch