Lowell Corporation Mechanical Ratchet Clutches, Model 78

Rugged and reliable for heavy-duty applications
Lowell ratchet clutches are designed from standard bodies, gears, pawls, and springs. Forces are applied in an optimum manner between the solid steel gear and hefty pawl so that loads are in compression rather than in shear. Gears are a low-carbon steel. Rugged tooth design as large contact area with pawl.

  • Mounting holes provided in body
  • Keyways are per ANSI/ASME B17.1
  • Lubrication is recommended after every 1200 hours of operation
  • Specials may be ordered with size, shape, and tooth arrangements of your choice
  • Fully locked neutral position
  • Free running neutral position available on request
  • Durable, cast iron construction
  • Custom models available
  • 100% made in USA
ImageOpeningPart NumberGear TeethMax TorqueOverrunning SpeedMaterialABCDEFGHJMeasurement Systemhf:att:pa_socket-openinghf:att:pa_gear-teethhf:att:pa_max-torquehf:att:pa_overrunning-speedhf:att:pa_materialhf:att:pa_ahf:att:pa_bhf:att:pa_chf:att:pa_dhf:att:pa_ehf:att:pa_fhf:att:pa_ghf:att:pa_hhf:att:pa_jhf:att:pa_measurement-system
Model 78 Ratchet Clutch - Square Gear Opening
3-1/4" Sq78901-98252246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Standard3-1-4-sq246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32standard
Model 78 Ratchet Clutch - Square Gear Opening
3-1/2" Sq78901-98256246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Standard3-1-2-sq246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32standard
Model 78 Ratchet Clutch - Square Gear Opening
3-3/4" Sq78901-98260246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Standard3-3-4-sq246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32standard
Model 78 Ratchet Clutch - Square Gear Opening
3-7/8" Sq78901-98262246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Standard3-7-8-sq246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32standard
Model 78 Ratchet Clutch - Square Gear Opening
95 mm Sq78901-M8295246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Metric95-mm-sq246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32metric
Model 78 Ratchet Clutch - Hex Gear Opening
3-7/8" Hex78901-98362246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Standard3-7-8-hex246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32standard
Model 78 Ratchet Clutch - Hex Gear Opening
4" Hex78901-98364246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Standard4-hex246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32standard
Model 78 Ratchet Clutch - Hex Gear Opening
4-1/8" Hex78901-98366246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Standard4-1-8-hex246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32standard
Model 78 Ratchet Clutch - Hex Gear Opening
4-1/4" Hex78901-98368246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Standard4-1-4-hex246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32standard
Model 78 Ratchet Clutch - Hex Gear Opening
4-1/2" Hex78901-98372246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Standard4-1-2-hex246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32standard
Model 78 Ratchet Clutch - Hex Gear Opening
4-5/8" Hex78901-98374246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Standard4-5-8-hex246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32standard
Model 78 Ratchet Clutch - Hex Gear Opening
100 mm Hex78901-N8300246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Metric100-mm-hex246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32metric
Model 78 Ratchet Clutch - Hex Gear Opening
105 mm Hex78901-N8305246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Metric105-mm-hex246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32metric
Model 78 Ratchet Clutch - Hex Gear Opening
110 mm Hex78901-N8310246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Metric110-mm-hex246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32metric
Model 78 Ratchet Clutch - Hex Gear Opening
115 mm Hex78901-N8315246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Metric115-mm-hex246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32metric
Model 78 Ratchet Clutch - Hex Gear Opening
120 mm Hex78901-N8320246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Metric120-mm-hex246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32metric
Model 78 Ratchet Clutch - Bore Gear Opening
2-3/4" Bore78901-98144246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Standard2-3-4-bore246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32standard
Model 78 Ratchet Clutch - Bore Gear Opening
70 mm Bore78901-M8170246260 lb-ft30 rpmCast Iron, Steel10-7/8"8-3/8"1-15/16"6-1/2"3-5/8"9-3/8"3-7/16"6-7/8"17/32"Metric70-mm-bore246260-lb-ft30-rpmcast-iron steel10-7-88-3-81-15-166-1-23-5-89-3-83-7-166-7-817-32metric