12.7 mm Bore Slip Rings (1/2 inch Through-Bore Series)
A hollow-shaft slip ring with a 12.7 mm (1/2 inch) centre bore — the smallest common through-bore size, for compact rotating heads, gimbals and robot end-effectors where a shaft or cable bundle has to pass through the axis.
Key specifications
Specifications
| Parameter | Value | Notes |
|---|---|---|
| Bore (through hole) | 12.7 mm | 1/2 inch nominal; matches standard 12 mm shafts with clearance |
| Available models | GK1233 (33 mm OD) / GK1256 (56 mm OD) | Compact vs full-circuit versions |
| Circuit count | GK1233: 2 / 6 / 8 · GK1256: 6 / 12 / 18 / 24 / 36 | Above 36 circuits requires a larger frame |
| Current per ring | 5 A / 10 A | Above 10 A use parallel rings or a bigger bore |
| Voltage | 440 V | Dielectric strength 800 VAC power / 300 VAC signal |
| Rotation speed | Up to 250 rpm | Confirm duty cycle for continuous running |
| Life expectancy | 20 / 50 / 80 million revolutions | Selected at order |
| Temperature | −30 to +80 °C | Special ranges on request |
| Protection | IP51 / IP65 / IP68 | Sealed variants for dust and washdown |
| Contact material | Six-element alloy wire, gold plated | Low-noise precious-metal contacts |
Typical applications
- Pan-tilt and gimbal heads — continuous rotation without cable wrap in a small envelope
- Robot end-effectors — tool power and signals through the wrist axis
- Small rotary indexers — 2 to 8 circuits on a compact frame
- Camera and sensor turrets — video and control signals on a rotating platform
- Medical and lab instruments — low-noise signal transfer in a sealed housing
Why choose between GK1233 and GK1256
Both share the 12.7 mm bore, so the shaft fit is identical — the choice comes down to how many circuits you need and how much space you have.
- GK1233 (33 mm OD) — 2, 6 or 8 circuits. Use it when the mounting envelope is tight and you only need a handful of power/signal paths. Smallest package in the through-bore range.
- GK1256 (56 mm OD) — 6 to 36 circuits. Use it when the same 12.7 mm shaft must carry many channels. The larger frame is what gives you the extra rings.
Frequently asked questions
Can I run 10 A on all 8 circuits at once?
Yes, as long as the total heat is acceptable. Eight circuits at 10 A each is a significant thermal load in a 33 mm frame — send us the simultaneous current profile and we will confirm the design before quoting.
Is the bore really 12.7 mm or 12 mm?
It is 12.7 mm (1/2 inch). A 12 mm shaft fits with clearance; a 12.7 mm shaft is a tight fit and should be specified with tolerance.
Can I pass cables through the bore?
Yes — that is the main reason to choose a through-bore design. Keep the bundle smaller than the bore with room for bending radius.
Does a sealed version cost more?
IP65 and IP68 are sealed variants and are quoted per configuration. Tell us the environment and we will recommend the minimum class that works.
Related products
Need a 12.7 mm bore slip ring?
Tell us the circuit count, current per ring and what passes through the bore — you will get a technical answer, usually within 5 hours.
