The SK and SHF series are both types of shaft supports used to secure the ends of round linear guide shafts (like those used with SBR or linear ball bushings) to a mounting base. Their primary function is to lock the shaft axially and radially, preventing it from moving or rotating.
The difference between the two lies in their structural design, mounting orientation, and ease of assembly/disassembly.
| Feature | SK Shaft Support ("Self-Contained") | SHF Shaft Support ("Flange/Base Mount") |
| Shape/Design | Cube-like, often with mounting holes on the bottom. | Flanged base with mounting holes often perpendicular to the shaft (on the sides). |
| Mounting Orientation | Bottom-Mounted to the base plate. | Side-Mounted (often against the base's vertical face or end plate). |
| Shaft Retention | Clamping via set screws tightened perpendicular to the shaft. | Clamping via bolts/screws tightened perpendicular to the shaft. |
| Space Profile | Sits on top of the base, increasing the overall machine height. | Can be mounted to the side of the base, potentially saving vertical space. |
| Application | Most common, general-purpose end support. | Used for shaft ends where side access for mounting is preferable, or as end stops for supported rails. |
Detailed Differences and Selection Criteria
1. SK Shaft Supports (Standard Bottom Mount)
The SK unit is the most common, general-purpose shaft support.
Design: It typically resembles a small, sturdy block. The bottom has mounting holes to secure it to the base plate, and one or two set screws on the side are used to clamp and lock the linear shaft in place.
Best Used When:
- You are mounting the shaft directly onto a flat horizontal plate.
- You have easy access to tighten the bolts from the top down.
- Vertical space is not critically constrained, as the support block sits on the base.
2. SHF Shaft Supports (Flange/End Mount)
The SHF unit features a flange or wider base that allows for mounting perpendicular to the shaft's axis.
Design: The mounting holes are often on the sides or on a base flange that extends outwards, allowing the unit to be mounted to a vertical surface, such as the end-plate of a machine frame.
Best Used When:
- You need to secure the shaft against a vertical face or the end wall of a machine frame.
- You are trying to minimize the overall height of the machine, as the SHF unit can often sit flush with the base plate (mounted to the end).
- You are using the support as a mechanical end-stop for a supported rail assembly.