50B40 40-Tooth #50 Roller Chain Sprocket – 1" Bore, 1/4" Keyway

The 50B40 is a heavy-duty 40-tooth roller chain sprocket designed for ANSI #50 single-strand roller chain and compatible 1" keyed shafts.

Its finished 1" bore and 1/4" keyway provide a secure mechanical connection between the sprocket and shaft, making it suitable for commercial garage door operators, industrial overhead door drive systems, gate operators, jackshaft assemblies, and other mechanical power-transmission applications.

Product Features

• 40-tooth roller chain sprocket

• Designed for ANSI #50 roller chain

• 1" finished bore

• 1/4" keyway

• Keyway timed with centerline of tooth

• Designed for keyed shaft installation

• Suitable for commercial and industrial drive systems

• Replacement sprocket for compatible operator assemblies

• Heavy-duty mechanical power-transmission component

Specifications

• Model / Size: 50B40

• Product Type: Roller Chain Sprocket

• Number of Teeth: 40

• Chain Size: ANSI #50

• Chain Pitch: 5/8"

• Bore: 1"

• Keyway: 1/4"

• Number of Strands: Single

• Application: Commercial Door, Gate & Mechanical Drive Systems

Common Applications

Suitable for compatible:

• Commercial garage door operators

• Industrial overhead door operators

• Jackshaft operator systems

• Gate operators

• Chain-reduction assemblies

• Mechanical drive systems

• Shaft-driven equipment

• Replacement sprocket applications

40-Tooth Configuration

Sprocket tooth count affects the operating ratio of a chain-drive system.

A 40-tooth sprocket may be used as either a driven or drive sprocket depending on the specific mechanical design. Changing sprocket tooth count can alter shaft speed, torque, and overall system performance.

For replacement applications, always match the existing sprocket tooth count unless the drive system has been specifically engineered for a different ratio.

Compatibility & Matching

Before ordering, verify:

• Chain Size: #50

• Number of Teeth: 40

• Shaft Diameter: 1"

• Keyway: 1/4"

Do not select a replacement sprocket based only on overall diameter or tooth count.

A sprocket with the wrong chain pitch, bore, or keyway will not be a direct replacement even if it appears visually similar.

#50 Roller Chain Compatibility

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

It should not be substituted for sprockets designed for #40, #41, #60, or other roller-chain sizes.

Package Contents

• 1 – 50B40 40-Tooth 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 door or driven equipment before servicing any operator or chain-drive assembly.

Inspect the roller chain, shaft key, bearings, and mating sprockets for wear when replacing a sprocket. Proper sprocket alignment and chain tension are important for smooth operation and long component life.