SCS12 Aluminum Shaft Collar – 12 mm Bore, 4 mm Keyway, Single Split Clamp Ring
Among the most frequently specified models in the SCS range, the SCS12 shaft collar serves the 12 mm shaft — one of the most common diameters in industrial automation. Whether ball-screw assemblies, linear guide carriages, or compact gearmotors, the 12 mm shaft is a foundational dimension in modern machine building. The SCS12 provides a 4 mm keyway that accepts wider keys capable of transmitting higher torques than the 3 mm keyway of the SCS10.
All three collars — SCS10, SCS12, and SCS13 — share the 30 mm OD and 10 mm face width envelope, enabling design standardisation of the mounting recess across machines using mixed shaft diameters from 10 to 13 mm.
Technical Specifications – SCS12
| Parameter | Value | Notes |
|---|---|---|
| Model | SCS12 | Single-split clamp type |
| Bore (d) | 12 mm | Fits Ø12 shafts |
| Outer Diameter (D) | 30 mm | Wall thickness 9.0 mm per side |
| Width (B) | 10 mm | Axial face width |
| Clamping Screw | M4 | Countersunk socket-head cap screw |
| Slit Width (W) | 1.5 mm | Opening gap for shaft insertion |
| Keyway (K) | 4 | Standard; custom keyway on request |
| Material | Aluminium alloy | ~2.7 g/cm³, corrosion resistant |
Design Features and Performance Advantages
⭐ Most Specified Mid-Range Bore
12 mm is the dominant shaft size in industrial automation; SCS12 is stocked at highest volume in the series.
🔧 4 mm Keyway, ISO Standard
Wider than SCS10's 3 mm slot; accepts DIN 6885A 4×4 keys for higher-torque drive applications.
◯ Shared Envelope with SCS10/13
30 mm OD × 10 mm wide — same mounting pocket as adjacent series models.
⚡ Bilateral Clamping Technique
Two SCS12 collars flanking a hub replace machined shaft shoulders, cutting lead time in prototype builds.
Application Sectors
▶ Ball-Screw and Lead-Screw Assemblies
12 mm is the shaft end size of many ball-screws in CNC machining centres, 3D printers, and laser cutters. An SCS12 at the bearing-support end prevents axial creep of the bearing housing under preload, maintaining positioning accuracy over the machine's service life.
▶ Modular Conveyor Roller Drives
In modular conveyors used in automotive assembly and e-commerce fulfilment, roller drive shafts of 12 mm are connected to zone-control motors via flexible couplings. The SCS12 prevents the coupling from walking off the shaft during reversals and direction changes.
▶ Collaborative Robot Tool Changers
Tool-changer mechanisms on collaborative robots frequently use 12 mm alignment pins and actuator shafts. Positioning an SCS12 as a hard-stop gives the tool-change sequence a repeatable mechanical datum independent of controller software.
Installation and Mounting Notes
The 4 mm keyway is designed to ISO 773 / DIN 6885A for a 4×4 parallel key — handling torque loads from compact servo drives, timing belt drives, and small conveyor roller shafts. Two SCS12 collars deployed as a bilateral clamping pair on either side of a ball-screw nut housing is a widely adopted technique in linear actuator design: it eliminates machined housing shoulders, allows positional fine-tuning after assembly, and provides a reliable axial reaction point for lead-screw thrust load. Contact the EP contacts page for bulk pricing on collar pairs.
Frequently Asked Questions – SCS12
How does the SCS12 compare to a circlip for axial shaft retention?
A circlip sits in a machined groove and is non-adjustable. The SCS12 is fully repositionable without shaft rework — critical in prototype or frequently reconfigured machinery. It also exerts distributed clamping force rather than a concentrated groove-edge load, reducing shaft fatigue.
Is the 4 mm keyway pre-cut or machined to order?
The keyway is machined to order. Standard delivery is without keyway. Specify K=4 mm on your purchase order or custom drawing. Standard keyway width tolerance is JS9.
Can the SCS12 withstand wash-down cleaning in food-processing environments?
Standard aluminium alloy tolerates water spray and mild detergent. For aggressive CIP chemicals or high-pressure steam, request an anodised or stainless steel variant.
What is the recommended tightening torque for the M4 clamping screw?
For M4 socket-head cap screws in aluminium: 2.5–3.0 N·m with a calibrated torque wrench. Exceeding 3.5 N·m risks thread strip-out.
Specify the SCS12 for Your Automation Project
MOQ 100 pcs | 4mm keyway available | Custom drawings accepted