Product Comparison
Taper Lock Bushing vs QD Bushing: Key Differences and How to Choose
Product Comparison
Taper Lock and QD bushings solve the same broad problem—mounting a rotating component on a shaft—but they are not two names for one interface. The mating hub geometry, flange arrangement and fastener positions differ, so the machine usually tells you which family belongs there.
For a new design, the choice can be made around available hub products, space and service requirements. For replacement work, start with the existing sheave, sprocket or hub and identify its interface before comparing bore ranges or price.
What is a Taper Lock bushing?
The EP Taper Lock range uses a compact tapered interface with tightening and removal-hole positions that vary across the model range. Smaller models use set-screw arrangements, while larger models move to socket-head cap screws. The bushing and mating component must be selected as a matched taper system.
What is a QD bushing?
QD bushings use a split flange/barrel arrangement and dedicated QD mating components. The EP QD range includes lettered sizes and standard or shallow keyway references. QD weld-on hubs can also be incorporated into fabricated sprockets or plates when the QD size and drilling arrangement are chosen before fabrication.
Side-by-side comparison
| Decision point | Taper Lock | QD |
|---|---|---|
| Mating interface | Compact taper-lock hub bore matched to the EP series. | QD flange/barrel interface matched to the QD size. |
| Model identification | Numbered series such as EP-2517 or EP-4040. | Lettered QD series such as EP-SF-STL or EP-J-STL. |
| Removal | Uses designated removal/jack positions for the taper-lock design. | Uses the QD screw/flange arrangement specified for that family. |
| Fabricated hub option | Taper-bore weld-on and bolt-on hub families are available. | QD Type 1 and Type 2 weld-on hubs are available. |
| Replacement rule | Match the taper-lock hub and bushing series. | Match the QD hub/sheave/sprocket and QD size. |
When Taper Lock is the natural choice
Use Taper Lock when the pulley, sprocket, hub or adapter is already designed around that taper family, or when a new component is being selected from a matching taper-bore system. The numbered range also spans compact through very large models, which makes family continuity useful in plant standards.
When QD is the natural choice
Choose QD when the driven component is built around a QD interface, when a QD weld-on hub is part of a fabricated design, or when the installed machine already uses the QD lettered system. Service convenience is a benefit only when the surrounding machine provides access to the required screw positions.
Can they be used interchangeably?
Not as a direct swap in the same hub. Even if two bushings accept the same shaft diameter, the outside taper, flange and fastener geometry must match the mating component. Converting from one family to another usually means changing the hub, sheave, sprocket or fabricated interface as well.
Frequently asked questions
Can I select between QD and Taper Lock only from shaft diameter?
No. Shaft bore is one variable. The mating hub or driven component must also match the selected bushing family.
Which family is easier to remove?
Both are designed as removable connections. Actual serviceability depends on the exact design and the access available in the machine.
Related products and resources
Need help with a real application?
Send the model, shaft diameter, keyway or drawing so the enquiry can be checked against the correct bushing family.