Lowell Corporation Mechanical Ratchet Clutches, Model 77

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 77 Ratchet Clutch - Square Gear Opening
2-1/8" Sq77901-97234244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Standard2-1-8-sq244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32standard
Model 77 Ratchet Clutch - Square Gear Opening
2-1/2" Sq77901-97240244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Standard2-1-2-sq244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32standard
Model 77 Ratchet Clutch - Square Gear Opening
2-3/4" Sq77901-97244244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Standard2-3-4-sq244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32standard
Model 77 Ratchet Clutch - Square Gear Opening
2-7/8" Sq77901-97246244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Standard2-7-8-sq244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32standard
Model 77 Ratchet Clutch - Square Gear Opening
2-15/16" Sq77901-97247244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Standard2-15-16-sq244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32standard
Model 77 Ratchet Clutch - Square Gear Opening
3" Sq77901-97248244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Standard3-sq244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32standard
Model 77 Ratchet Clutch - Square Gear Opening
3-1/8" Sq77901-97250244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Standard3-1-8-sq244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32standard
Model 77 Ratchet Clutch - Square Gear Opening
3-1/4" Sq77901-97252244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Standard3-1-4-sq244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32standard
Model 77 Ratchet Clutch - Square Gear Opening
70 mm Sq77901-M7270244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Metric70-mm-sq244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32metric
Model 77 Ratchet Clutch - Square Gear Opening
75 mm Sq77901-M7275244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Metric75-mm-sq244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32metric
Model 77 Ratchet Clutch - Square Gear Opening
80 mm Sq77901-M7280244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Metric80-mm-sq244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32metric
Model 77 Ratchet Clutch - Hex Gear Opening
3-1/4" Hex77901-97352244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Standard3-1-4-hex244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32standard
Model 77 Ratchet Clutch - Hex Gear Opening
3-1/2" Hex77901-97356244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Standard3-1-2-hex244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32standard
Model 77 Ratchet Clutch - Hex Gear Opening
3-3/4" Hex77901-97360244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Standard3-3-4-hex244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32standard
Model 77 Ratchet Clutch - Hex Gear Opening
3-7/8" Hex77901-97362244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Standard3-7-8-hex244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32standard
Model 77 Ratchet Clutch - Hex Gear Opening
85 mm Hex77901-M7385244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Metric85-mm-hex244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32metric
Model 77 Ratchet Clutch - Hex Gear Opening
90 mm Hex77901-M7390244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Metric90-mm-hex244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32metric
Model 77 Ratchet Clutch - Hex Gear Opening
95 mm Hex77901-M7395244100 lb-ft50 rpmCast Iron, Steel9-3/4"7-1/2"1-1/2"6"3-1/8"8-7/16"3-1/8"6-1/4"17/32"Metric95-mm-hex244100-lb-ft50-rpmcast-iron steel9-3-47-1-21-1-263-1-88-7-163-1-86-1-417-32metric