Liftmaster K19-50040, CHAIN, #50
The LiftMaster K19-50040 is a #50 roller chain service part used in the drive assembly of select CSW200 Series commercial swing gate operators. In this type of operator, the chain is part of the power-transfer path between the motor, gearbox, and moving gate mechanism. A worn chain can create slop in gate movement, uneven starts, skipped teeth, noisy operation, or drive system binding.
This part is best handled as a parts-diagram replacement rather than a generic chain purchase. The chain pitch, length, connection style, and location in the operator matter. CSW200 operators have been sold across multiple generations, including older Elite-branded versions and LiftMaster-labeled versions, so the safest way to order is to match the original K19-50040 number or verify the chain callout on the operator breakdown.
Compatible With
- Select LiftMaster CSW200 Series commercial swing gate operators
- Select Elite CSW200 Series swing gate operator assemblies
- Commercial swing gate drive assemblies using the K19-50040 #50 chain callout
- Related CSW200 parts diagrams where K19-50040 is shown as the required chain
Compatibility note: Do not substitute this chain only by visual size. Confirm the operator model, chain number, and parts diagram because other CSW200 chain positions may use different numbers, including Q044 / K19-50048.
Features and Specifications
| Manufacturer | LiftMaster / Chamberlain Group |
| Product Type | #50 drive chain |
| Part Number | K19-50040 |
| Application | Commercial swing gate operator drive system |
| Compatible Operator Type | Select CSW200 Series swing gate operators |
| Chain Size | #50 |
| Notes | High-tensile roller chain for operator drivetrain service |
Also Known As / Related Part Numbers
- K19-50040
- 19-50040
- LM-K19-50040
- LiftMaster K19-50040
- Elite CSW200 #50 chain reference
Technician Note
Inspect sprockets, tensioning hardware, bearings, and gearbox alignment when replacing a stretched or damaged chain. A new chain installed over worn sprockets can wear quickly or continue to run noisy.
Before Ordering Checklist
- Match the original part number to K19-50040 if available
- Confirm the operator is a CSW200 Series swing gate operator
- Compare chain size and chain position against the parts diagram
- Inspect sprockets before installing a new chain
- Do not order this as a universal replacement for every LiftMaster #50 chain
Professional Advisory
Gate operator drivetrain work can involve stored mechanical force and powered equipment. Disconnect power and have a qualified gate technician service the operator if the gate is binding, the chain is jumping, or high-voltage motor wiring must be accessed.
Product Questions and Answers
Is K19-50040 the same as K19-50048?
No. Both are #50 chain references used around CSW200-style operators, but K19-50040 and K19-50048 / Q044 are different service part numbers and should be matched by the parts diagram.
What symptoms can point to a worn gate operator chain?
Common symptoms include jerky movement, chain slap, popping sounds, visible rust, stretched chain links, loose tension, or the gate failing to move smoothly under load.
Can I cut a generic #50 chain to replace this part?
For best fit, use the specified LiftMaster service part or match the exact chain callout. Chain length, connector style, and operator position matter.
Does this fit all CSW200 operators?
It is commonly associated with CSW200 Series swing gate operators, but model generation and chain position should be checked before ordering.
Should sprockets be replaced at the same time?
If the sprocket teeth are hooked, worn, chipped, or misaligned, replacing only the chain may not solve the problem.
