Lowell Corporation Mechanical Ratchet Clutches, Model 71

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 71 Ratchet Clutch - Square Opening
3/8" Sq71901-9120616200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Standard3-8-sq16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64standard
Model 71 Ratchet Clutch - Square Opening
1/2" Sq71901-9120816200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Standard1-2-sq16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64standard
Model 71 Ratchet Clutch - Square Opening
9/16" Sq71901-9120916200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Standard9-16-sq16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64standard
Model 71 Ratchet Clutch - Square Opening
5/8" Sq71901-9121016200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Standard5-8-sq-216200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64standard
Model 71 Ratchet Clutch - Square Opening
10 mm Sq71901-M121016200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Metric10-mm-sq16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64metric
Model 71 Ratchet Clutch - Square Opening
13 mm Sq71901-M121316200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Metric13-mm-sq16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64metric
Model 71 Ratchet Clutch - Square Opening
14 mm Sq71901-M121416200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Metric14-mm-sq16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64metric
Model 71 Ratchet Clutch - Square Opening
16 mm Sq71901-M121616200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Metric16-mm-sq16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64metric
Model 71 Ratchet Clutch - Hex Opening
1/2" Hex71901-9130816200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Standard1-2-hex16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64standard
Model 71 Ratchet Clutch - Hex Opening
9/16" Hex71901-9130916200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Standard9-16-hex16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64standard
Model 71 Ratchet Clutch - Hex Opening
5/8" Hex71901-9131016200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Standard5-8-hex16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64standard
Model 71 Ratchet Clutch - Hex Opening
3/4" Hex71901-9131216200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Standard3-4-hex16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64standard
Model 71 Ratchet Clutch - Hex Opening
13 mm Hex71901-M131316200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Metric13-mm-hex16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64metric
Model 71 Ratchet Clutch - Hex Opening
14 mm Hex71901-M131416200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Metric14-mm-hex16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64metric
Model 71 Ratchet Clutch - Hex Opening
16 mm Hex71901-M131616200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Metric16-mm-hex16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64metric
Model 71 Ratchet Clutch - Hex Opening
17 mm Hex71901-M131716200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Metric17-mm-hex16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64metric
Model 71 Ratchet Clutch - Hex Opening
19 mm Hex71901-M131916200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Metric19-mm-hex16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64metric
Model 71 Ratchet Clutch - Bore Opening
1/2" Bore71901-9110816200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Standard1-2-bore16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64standard
Model 71 Ratchet Clutch - Bore Opening
5/8" Bore71901-9111016200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Standard5-8-bore16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64standard
Model 71 Ratchet Clutch - Bore Opening
3/4" Bore71901-9111216200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Standard3-4-bore16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64standard
Model 71 Ratchet Clutch - Bore Opening
13 mm Bore71901-M111316200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Metric13-mm-bore16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64metric
Model 71 Ratchet Clutch - Bore Opening
16 mm Bore71901-M111616200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Metric16-mm-bore16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64metric
Model 71 Ratchet Clutch - Bore Opening
19 mm Bore71901-M111916200 lb-ft250 rpmCast Iron, Steel2-7/8"2-3/8"15/16"1-3/4"13/16"2-1/4"7/8"1-3/4"17/64"Metric19-mm-bore16200-lb-ft250-rpmcast-iron steel2-7-82-3-815-161-3-413-162-1-47-81-3-417-64metric