GBC-SCS40 Aluminum Clamp Type Shaft Collar – 40mm Bore
The GBC-SCS40 aluminum clamp-type shaft collar fits 40 mm bore shafts. OD 70 mm, face width 18 mm, M8 clamping screw delivering up to 18 N·m, optional 12 mm keyway. Engineered for large helical gearbox outputs, CNC rotary table drives, and industrial centrifuge main shaft assemblies requiring 4–6 kN axial retention.
MOQ: 50 pcs. Minimum order value USD 1,500; mixed orders and trial quantities welcome.
40mm Bore Aluminum Clamp Shaft Collar – M8 High-Force Clamping for Large Gearbox & Rotary Table Drives
| Parameter | Value | Note |
|---|---|---|
| SKU / Model | GBC-SCS40 | GBC SCS Series — Large Bore |
| Bore Diameter (d) | 40 mm | Shaft h6 tolerance: 40.000 / 39.984 mm |
| Outer Diameter (D) | 70 mm | Provides thick wall for high-clamp loads |
| Face Width (B) | 18 mm | Extended width for high axial bearing area |
| Clamping Screw | M8 socket-head cap screw | Torque: 16–18 N·m · 8 mm hex key |
| Slot Width (W) | 2.0 mm | Wide slot for easy assembly over shaft features |
| Keyway Width (K) | 12 mm | DIN 6885 Form A; plain bore is default supply |
| Recommended Torque | 16–18 N·m | Use calibrated torque wrench |
| Material | Aluminium alloy | Hard-anodize, electroless nickel & steel variants available |
| MOQ | 100 pcs | Custom engineering drawings accepted |
Product Overview
The GBC-SCS40 enters large-bore territory with a configuration purpose-built for the demands of heavy industrial shaft assemblies: 40 mm bore, 70 mm OD, 18 mm face width, and an M8 socket-head cap screw that delivers clamping torque up to 18 N·m — more than double the M6 maximum used in SCS30 and SCS35. This combination of enlarged OD, extended face width, and high-torque screw produces axial holding forces in the 4–6 kN range on properly toleranced h6 shafts, placing the SCS40 firmly within the specification range of large helical and bevel-helical gearbox output shafts, rotary table drives in machining centres, and the main shaft assemblies of industrial centrifuges and mixers. The 12 mm keyway — machined to DIN 6885 Form A for 40 mm bore — allows the collar to function as both a precision axial locator and a full-torque rotational coupling element, consolidating two separate shaft components into one and reducing assembly part count in drive trains where every kilogram of rotating mass carries an energy cost.
Key Features
Non-Damaging Clamp Design
Circumferential clamping force eliminates shaft surface indentation, preserving ground shaft finishes and protecting adjacent seals and bearings from the accelerated wear caused by the stress-concentration marks that set-screw collars leave on large-diameter shafts where replacement cost is high.
M8 High-Capacity Clamping Screw
The M8 socket-head cap screw delivers clamping torque up to 16–18 N·m — the highest in the SCS range at this bore level — producing axial holding forces that match the sustained thrust loads of large industrial machinery operating continuously at rated capacity.
2.0 mm Wide Slot — Field Assembly Advantage
The 2.0 mm slot width provides generous bore clearance for sliding the collar over shaft keyways, threads, and groove features without tools or force — a significant advantage on large shaft assemblies built in the field without alignment fixtures or heating equipment.
18 mm Face Width — Maximum Axial Bearing Area
The 18 mm face width is matched to the bore and OD at this size to deliver the highest axial bearing area in the SCS range, distributing clamping contact pressure across a wide band that maximises holding force and minimises bore surface pressure under long-term sustained axial loads.
12 mm DIN 6885 Keyway — Full-Torque Locking Option
The 12 mm keyway follows DIN 6885 Form A for 40 mm bore, providing both axial location and full-rated rotational torque transmission through a single component. Specify at order — default supply is plain bore without keyway.
Typical Application Scenarios
Large Helical Gearbox Output Shaft Location
Helical and bevel-helical gearboxes in the 5.5–15 kW class typically output through 40 mm shafts. The SCS40 positions the driven coupling half against the gearbox output bearing, providing a positive thrust face that prevents coupling walk under the sustained axial forces generated by helical gear mesh — forces that single-stage helical gearboxes produce continuously at full rated load.
Rotary Table & Indexing Drive Assemblies
CNC rotary tables and rotary indexing units in multi-axis machining centres route drive torque through 40 mm worm or hypoid gear output shafts. The SCS40 with keyway locates the table drive coupling at the required radial and axial position, maintaining the sub-0.01 mm angular positioning repeatability that tool-path accuracy demands across multi-hour continuous machining cycles.
Industrial Centrifuge & Mixer Main Shafts
Decanter centrifuges and industrial paddle mixers in chemical, pharmaceutical, and food-processing plants mount impeller and scroll assemblies on 40 mm main shafts. The SCS40 clamp collar holds impeller-hub positions against the axial loads generated by process fluid viscosity and density changes, avoiding the shaft bending and bearing overload that impeller migration would produce during high-density batch processing.
Dimensional Guide & Shaft Fit Specification
The GBC-SCS40 is defined by bore d = 40 mm, outer diameter D = 70 mm, and face width B = 18 mm. The 2.0 mm slot runs the full face width, providing the radial flex gap that allows the bore to close around the shaft as the M8 screw is tightened to 16–18 N·m. Specify the mating shaft to ISO 286 h6 (40.000 / 39.984 mm) for the optimal pre-installation sliding fit and maximum post-clamping axial retention force. Bore sizes above 40 mm must be verified with a calibrated bore gauge rather than relying on nominal dimensions — manufacturing tolerances on large shafts can approach 0.05 mm and will significantly affect clamping performance if outside the h6 band.
GBC supplies custom configurations including steel and stainless steel construction, extended face widths, twin-screw clamping, marine-grade anodizing, and bore sizes above 60 mm. Contact the GBC team via the enquiry page with your engineering drawing and application details for a tailored quotation.
Model Selection Guide
For 35 mm shafts in heavy conveyor and mining duty, the GBC-SCS35 at 60 mm OD with M6 screw is the predecessor. Stepping up to 45 mm bore — where the clamping screw escalates to M10 and face width reaches 22 mm for maximum heavy-industrial retention — the GBC-SCS45 is the appropriate choice for ship auxiliary machinery and heavy-industry transmission systems.
| Model | Bore | Relation |
|---|---|---|
| GBC-SCS35 | 35mm | ← Smaller |
| GBC-SCS40 | 40 mm | ◀ Current |
| GBC-SCS45 | 45mm | → Larger |
Installation Procedure
- Shaft measurement: Measure the shaft diameter at the collar location using a calibrated micrometer or bore gauge, confirming the dimension falls within ISO h6 (40.000 / 39.984 mm). At large bore sizes, do not assume nominal dimensions — verify physically.
- Surface preparation: Degrease the clamping zone with a solvent wipe. For shafts with light rust or scale, polish with 400-grit abrasive cloth before degreasing. Remove all burrs from keyway edges to prevent bore scoring during collar installation.
- Collar positioning: Open the slot fully by backing off the M8 screw two full turns. Slide the GBC-SCS40 onto the shaft to the required position, referencing a pre-set depth gauge or spacer for repeatable placement. Torque M8 screw to 16–18 N·m using a calibrated torque wrench with a 6 mm hex-bit socket. For rotary-table applications, verify collar position with a dial indicator on the table face — lateral movement during clamping must not exceed 0.005 mm.
- Torqued clamping: Using a calibrated torque wrench with a 8 mm hex-bit socket, tighten the M8 screw in three steps — 30%, 70%, then 16–18 N·m — checking position after each step. Mark the screw head with a paint pen after final tightening to detect any self-loosening during subsequent inspections.
Frequently Asked Questions
Can the SCS40 replace a steel shaft collar for holding a heavy coupling on a gearbox output shaft?
What M8 screw torque should be applied to the SCS40?
How does the 18mm face width in SCS40 compare to the 15mm in SCS35?
Related Products
Browse adjacent sizes and associated shaft components from GBC:
- GBC-SCS35 – 35mm bore aluminum clamp shaft collar — next smaller size in the heavy-bore SCS range
- GBC-SCS45 – 45mm bore aluminum clamp shaft collar — next larger size for maximum axial capacity
- Complete GBC SCS Shaft Collar Series — all standard bore sizes from 6 mm to 60 mm, with custom options beyond
Request a Quote or Discuss a Custom Specification
Minimum order quantity is 100 pcs. GBC supplies steel and stainless steel variants, marine-grade hard-anodizing, extended face widths, twin-screw configurations, and custom bore sizes above 60 mm. Supply your engineering drawing for a precise quotation.
The GBC-SCS40 aluminum clamp-type shaft collar fits 40 mm bore shafts. OD 70 mm, face width 18 mm, M8 clamping screw delivering up to 18 N·m, optional 12 mm keyway. Engineered for large helical gearbox outputs, CNC rotary table drives, and industrial centrifuge main shaft assemblies requiring 4–6 kN axial retention.
MOQ: 50 pcs. Minimum order value USD 1,500; mixed orders and trial quantities welcome.
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