SCS18 Aluminum Shaft Collar – 18 mm Bore, OD 40 mm, 6 mm Keyway for Heavy-Duty Drives
The SCS18 shaft collar steps up to an outer diameter of 40 mm — a significant jump from the 35 mm OD of the SCS16 — to provide the larger clamping circumference that an 18 mm shaft demands. The 6 mm keyway on the SCS18 is the first in the series to match the 6×6 parallel key standard (DIN 6885A) that appears on heavy-duty industrial gearmotors, packaging machinery drives, and agricultural equipment output shafts.
Where the 5 mm key of the SCS14–16 range handles medium drive duty, the 6 mm key of the SCS18 crosses the threshold into genuine power transmission territory, capable of resisting the torsional loads from multi-kilowatt direct drives.
Technical Specifications – SCS18
| Parameter | Value | Notes |
|---|---|---|
| Model | SCS18 | Single-split clamp type |
| Bore (d) | 18 mm | Fits Ø18 shafts |
| Outer Diameter (D) | 40 mm | Wall thickness 11.0 mm per side |
| Width (B) | 12 mm | Axial face width |
| Clamping Screw | M5 | Countersunk socket-head cap screw |
| Slit Width (W) | 1.5 mm | Opening gap for shaft insertion |
| Keyway (K) | 6 | Standard; custom keyway on request |
| Material | Aluminium alloy | ~2.7 g/cm³, corrosion resistant |
Design Features and Performance Advantages
▲ OD Grows to 40mm
Step-up from 35mm provides larger clamping circumference — more friction area per unit clamp force.
⚙ 6mm DIN 6885A Keyway
Matches the 6×6 parallel key standard on industrial gearmotors — genuine power transmission capability.
📈 Lower Maintenance Frequency
Larger contact area means less micro-slip under vibration — collar stays in position longer between re-torque intervals.
⚡ Agricultural-Grade Durability
Aluminium alloy resists corrosion in outdoor and damp field conditions.
Application Sectors
▶ Packaging Machinery High-Cycle Drives
Horizontal and vertical form-fill-seal packaging machines run servo-driven film-advance shafts at 18 mm. The SCS18 holds the film-advance roller in axial position through millions of pack cycles, and the 6 mm keyway prevents the roller hub from rotating under film tension torque.
▶ Agricultural Equipment Power Take-Off Shafts
Compact tractor attachments and self-propelled harvesting equipment use 18 mm shafts in their internal drive trains. The SCS18's M5 clamping force and 6 mm keyway capability survive the shock loads and continuous vibration of field operation.
▶ Woodworking and Furniture Manufacturing Spindle Drives
Tenoner and routing machines in furniture production run cutting spindles on 18 mm drive shafts. Positioning the SCS18 as an outboard collar behind the spindle bearing housing prevents the cutter arbour from walking under the axial cutting force component.
Installation and Mounting Notes
The transition to 40 mm OD improves the SCS18's resistance to axial displacement under cyclic vibratory loads. A larger contact surface between collar and shaft means the static friction force resisting slippage is proportionally higher, even at the same M5 clamping torque. Two SCS18 collars in a paired arrangement effectively secure chain sprockets or V-belt pulleys on 18 mm shafts without machined shaft shoulders, and can be adjusted to fine-tune pulley lateral alignment — critical in multi-strand drive systems. Contact EP for custom keyway depth or modified slit geometry options.
Frequently Asked Questions – SCS18
Why does the OD jump from 35mm to 40mm at the SCS18?
An 18 mm bore in a 35 mm OD collar would leave only 8.5 mm of wall per side — below the minimum recommended for reliable split-clamp closure force. The 40 mm OD restores the wall to 11 mm per side, maintaining the bore-closure geometry needed for rated clamping performance.
Can the SCS18 be used without a keyway on a smooth shaft?
Yes. Standard delivery is without keyway. Friction clamp alone is adequate for purely axial positioning and moderate torque loads. For drives above approximately 15 N·m of shaft torque, the keyway option is recommended.
What key size is compatible with the SCS18 keyway?
The 6 mm keyway is sized for DIN 6885A 6×6 parallel keys. Select key length to match the hub engagement length.
Is the SCS18 suitable for outdoor agricultural environments?
Aluminium alloy is inherently corrosion-resistant to moisture and mild chemicals. For extended outdoor exposure to fertiliser spray or salt-spray environments, specify anodised surface treatment at order time.
Order SCS18 for Agricultural and Packaging Drives
MOQ 100 pcs | 6mm keyway available | Anodised finish on request