Keyless locking assemblies (also known as shaft locking devices, shrink discs, or clamping elements) are essential components for secure, backlash-free shaft-to-hub connections in heavy-duty industrial applications. They eliminate the need for keyways, reducing stress concentrations and enabling easy installation and removal.

This guide explains how keyless locking assemblies work, their key advantages over traditional keyways, and how to select the right model for your application – using the CSF-A18 series as a practical example.

1. What Is a Keyless Locking Assembly?

A keyless locking assembly is a mechanical device that creates a friction-lock connection between a shaft and a hub. It consists of:

• Tapered inner and outer rings

• Pressure rings

• High-strength clamping screws (12.9 grade)

When the screws are tightened, the tapered rings are forced together, creating high radial pressure that locks the hub onto the shaft. No keys, keyways, or threads are required.

✅ Keyless locking assemblies are also known as shaft locking devices, cone clamping elements, power locks, shrink discs, and keyless rigid couplings.

2. Keyless Locking Assembly vs Keyway – Key Differences

3. CSF-A18 – Key Features

The CSF-A18 series uses a double cone + mechanical wedge type tightening method:

4. Why Choose CSF-A18 Over Other Locking Assemblies?

Reason 1: Higher Clamping Force
The double cone + mechanical wedge design provides higher clamping force and greater torque capacity compared to single cone designs.

Reason 2: 12.9 Grade Screws
All CSF-A18 assemblies feature 12.9 grade high-strength screws – the highest strength class for metric screws – ensuring maximum clamping force and reliability.

Reason 3: Wide Size Range
Inner hole diameters from 25–320 mm – covering most industrial shaft sizes.

Reason 4: Overload Protection
Slips under extreme overload – protects connected equipment from damage.

Reason 5: Reusable
Can be disassembled and reinstalled multiple times without damage – reducing long-term costs.

5. Applications Where Keyless Locking Excels

6. Installation & Maintenance Tips

1. Clean shaft and hub bore – Remove oil, grease, and debris

2. Check dimensions – Ensure shaft and bore are within tolerance

3. Pre-center the assembly – CSF-A18 is not self-centering

4. Apply light oil to screws – Ensures accurate torque application

5. Tighten screws evenly – Use a torque wrench in a star pattern

6. No lubrication on tapered surfaces – Dry for maximum friction

7. For removal – Loosen screws evenly – no pullers required

8. Reusable – Can be reinstalled multiple times

7. Selection Checklist

• Shaft diameter: 25–320 mm – select the correct CSF-A18 model

• Torque requirement: 676–2930 N·m – ensure it exceeds your application torque

• Surface finish: Black oxide (standard) or nickel plating

• Centering: Not self-centering – pre-centering required

• Application: Manufacturing, packaging, mining, wind turbines, printing

8. Conclusion

The CSF-A18 keyless locking assembly from Apex Coupling offers superior performance compared to traditional keyways – with zero backlash, no shaft weakening, overload protection, easy installation, and reusability. With S45C steel construction, double cone + wedge design, 12.9 grade screws, and a wide size range from 25–320 mm, it is the ideal solution for manufacturing plants, packaging machinery, mining equipment, wind turbines, and general industrial power transmission.

👉 Need a keyless locking assembly for your application? Contact us with your shaft diameter, torque, and finish requirements.