Selecting the proper mechanical envelope for a rotary slip ring is one of the most fundamental decisions in machine design. The two most prominent structural architectures are Through-Bore (Hollow Shaft) Slip Rings and Capsule (Compact Cylindrical) Slip Rings. Understanding the trade-offs between space efficiency, central clearance, and circuit density is key to selecting the optimal rotary joint.
This technical guide evaluates the mechanical, electrical, and operational differences between Torquety’s SVTS C-Series (Through-Bore) and SVTS A-Series (Capsule) slip ring families.

Through-Bore Slip Rings (C-Series): Central Hollow Shaft Clearance
Through-Bore slip rings are designed with a hollow central hole ranging from 3 mm to over 100 mm. This open bore allows engineers to route secondary utilities directly through the center axis of rotation, such as:

Secure Your Components Stock Now with Torquety
Reliable automation components for high-performance applications.
- Pneumatic hoses or hydraulic fluid conduits.
- Rotating drive shafts or ball screws.
- Fiber optic rotary joints (FORJ) or microwave coax links.
⚙️ Ideal Applications for Through-Bore Slip Rings
Automated rotary indexing tables, packaging machinery, heavy cable reels, wind turbines, and robotics platforms requiring hybrid mechanical clearance.
Capsule Slip Rings (A-Series): Ultra-Compact High Density
Capsule slip rings feature a self-contained, end-shaft mounted cylindrical housing designed for tight space envelopes. By utilizing gold-on-gold miniature contact technology, capsule slip rings deliver high circuit density in outer diameters as small as 12 mm.
Architectural Comparison Matrix
| Feature / Parameter | Through-Bore Slip Rings (C-Series) | Capsule Slip Rings (A-Series) |
|---|---|---|
| Central Hole | Yes (3 mm to 100+ mm inner diameter) | No (Solid end-of-shaft mounting) |
| Outer Diameter | Medium to Large (35 mm – 200+ mm) | Ultra-Compact (12 mm – 30 mm) |
| Current Capacity | High (Up to 50A+ per power circuit) | Low to Medium (2A – 10A per circuit) |
| Typical Applications | Rotary tables, packaging, industrial automation | CCTV gimbals, medical tools, robotics joints |
“Choosing between Through-Bore and Capsule architectures comes down to central clearance needs vs. total volumetric envelope. Torquety offers tailored units across both product lines.”
Need a Custom Component Solution?
Contact our engineering team to discuss your application requirements and get a custom quote.

