LiftMaster 711550B32QGH 32-Tooth #50 Chain Sprocket – 1-1/4" Bore, 1/4" Keyway

The LiftMaster 711550B32QGH is a heavy-duty 32-tooth sprocket designed for compatible LiftMaster commercial garage door operators using ANSI #50 roller chain and a 1-1/4" keyed shaft.

Its finished 1-1/4" bore and 1/4" keyway provide a secure mechanical connection to the operator shaft, while the 32-tooth configuration maintains the drive ratio required by compatible commercial operator assemblies.

Product Features

• Genuine LiftMaster commercial operator sprocket

• 32-tooth configuration

• Designed for ANSI #50 roller chain

• 1-1/4" finished bore

• 1/4" keyway

• Designed for keyed shaft installation

• Suitable for compatible LiftMaster commercial operators

• Heavy-duty commercial drive component

• Replacement sprocket for compatible operator drive assemblies

Specifications

• Manufacturer: LiftMaster

• Part Number: 711550B32QGH

• Sprocket Size: 50B32

• Product Type: Roller Chain Sprocket

• Number of Teeth: 32

• Chain Size: ANSI #50

• Chain Pitch: 5/8"

• Bore: 1-1/4"

• Keyway: 1/4"

• Number of Strands: Single

• Application: Commercial Garage Door Operator Drive Systems

Compatible LiftMaster Operator Families

The 711550B32QGH is used with various compatible:

• LiftMaster Logic 4.0 commercial operators

• LiftMaster Logic 5.0 commercial operators

• LiftMaster MAXUM DC Standard-Duty operators

• LiftMaster MAXUM DC Industrial-Duty operators

• Other LiftMaster commercial operator configurations specifically calling for this sprocket

Compatibility depends on the exact operator model and drive configuration.

32-Tooth Configuration

Sprocket tooth count directly affects the operating ratio of the commercial door operator.

Changing from a 32-tooth sprocket to a different tooth count can alter:

• Shaft speed

• Door operating speed

• Available torque

• Chain geometry

• Overall operator performance

For replacement applications, match the original sprocket tooth count unless LiftMaster specifies otherwise for the exact operator configuration.

Compatibility & Matching

Before ordering, verify:

• Part Number: 711550B32QGH

• Chain Size: #50

• Number of Teeth: 32

• Shaft Diameter: 1-1/4"

• Keyway: 1/4"

Do not select a sprocket based only on tooth count or appearance.

LiftMaster also uses similar 32-tooth sprockets with:

• #41 chain

• 1" bore

• 1-1/4" bore

These sprockets are not automatically interchangeable.

#50 Roller Chain Compatibility

This sprocket is designed specifically for ANSI #50 roller chain, which uses a 5/8" pitch.

It should not be substituted for sprockets intended for #41 or other roller-chain sizes.

Always match the sprocket to the existing chain.

Keyed Shaft Connection

The 1/4" keyway accepts a compatible shaft key to mechanically connect the sprocket to the 1-1/4" operator shaft.

This keyed connection transfers torque between the shaft and sprocket and helps prevent independent rotation under load.

Package Contents

• 1 – LiftMaster 711550B32QGH 32-Tooth #50 Chain Sprocket

Roller chain, shaft, shaft key, bearings, operator, and other drive components are sold separately.

Important Installation Note

Disconnect electrical power and properly secure the commercial door before servicing the operator or chain-drive assembly.

Inspect the roller chain, shaft key, bearings, mating sprockets, and shaft for excessive wear during replacement.

Proper chain alignment and tension are important for reliable operator performance and long component life.