Through-bore slip rings
MOFLON MT Series through-bore slip rings
Standard through-bore slip rings with gold-plated rings and gold alloy fibre brushes, from a 3 mm bore (MT0317) to 300 mm (MT300476) in the catalogue table, up to 144 circuits and up to 690 V depending on size.
Key specifications
| Circuits (max) | 144 |
|---|---|
| Voltage (max) | 690 V |
| Bore | 3–300 mm |
| Outer diameter | 17–476 mm |
| Bore note | header quotes 3–800 mm with customisation; standard table tops out at 300 mm |
| Brushes | gold alloy fibre brushes |
Summarised in our own words from MOFLON Technology (legal entity name not stated on its website)'s published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1
Notes on this data
Current per ring, speed, IP and temperature not published on the series page (per-model datasheets exist).
Specify Motion is not affiliated with MOFLON Technology (legal entity name not stated on its website). MOFLON and MT Series through-bore slip rings are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Typical applications
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Our experienced engineers are on hand, ready to help with your project. Whether you need the MOFLON MT Series through-bore slip rings itself, help sourcing it, or a modified or custom design built around your load, speed and space, tell us what the machine has to do and we'll come back with the right option.
- Help sourcing MT Series through-bore slip rings and spares for installed machines
- Modified and custom designs when a catalogue part doesn't fit
- Complete axis: motor, drive, gearing and feedback matched together
What a through-bore slip ring is
A through-bore slip ring is a rotary electrical joint built around a hollow centre, so a drive shaft, pneumatic or hydraulic line, fibre or cable bundle can pass straight through it. The rings are mounted on an insulated sleeve that fits over or around the machine shaft, and the brush blocks sit outside them in a stationary housing. Power, signal and data circuits are combined in one unit, while the bore keeps the rotation axis available for mechanics or services. Bore sizes range from a few millimetres to hundreds of millimetres.
When engineers choose a through-bore slip ring
Engineers choose a through-bore design when the axis of rotation is already occupied, typically by a shaft, a rotary union or a cable that must stay continuous. It is the standard choice for indexing tables, wrapping machines and turntables built around a central column. The trade-off is that larger rings mean higher surface speed, more brush wear and more drag torque at the same rpm, and the unit is bigger than a capsule. Where axial length is the constraint rather than diameter, a pancake design may suit better.
How to specify the MOFLON MT Series through-bore slip rings
Send these with your enquiry and an engineer can confirm the right MT Series through-bore slip rings variant or an equivalent:
- Bore diameter and shaft tolerance (mm)
- Outer diameter and length limits (mm)
- Circuit count and current per circuit (A)
- Working voltage and any high-voltage isolation (V)
- Speed, continuous and peak (rpm)
- Data or bus protocols to pass, such as Ethernet, CAN or PROFINET
- Sealing (IP code), temperature (°C) and mounting method
Common mistakes to avoid
- Sizing the bore to the shaft only, with no allowance for a rotary union or cables that must also pass
- Mounting the rotor hard on a shaft with radial runout and a separate stator fixing, so the unit is forced to align two axes
- Forgetting that surface speed rises with diameter, so the rated rpm is lower for larger bores
- Not stating which circuits need screening or twisted pairs for encoder and fieldbus signals
MOFLON MT Series through-bore slip rings: frequently asked questions
What is the MOFLON MT Series through-bore slip rings?
Standard through-bore slip rings with gold-plated rings and gold alloy fibre brushes, from a 3 mm bore (MT0317) to 300 mm (MT300476) in the catalogue table, up to 144 circuits and up to 690 V depending on size. Published series figures include circuits 144, voltage 690 V, bore 3 mm, bore 300 mm. It is made by MOFLON Technology (legal entity name not stated on its website); Specify Motion can help source it or propose an equivalent.
Who makes the MOFLON MT Series through-bore slip rings?
The MOFLON MT Series through-bore slip rings is made by MOFLON (MOFLON Technology (legal entity name not stated on its website)) and is listed here for engineers comparing options. Specify Motion is not affiliated with MOFLON Technology (legal entity name not stated on its website); brand names are used only to identify the product.
What is the circuits of the MOFLON MT Series through-bore slip rings?
The published series maximum circuits is 144. Individual models and sizes in the MT Series through-bore slip rings range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the MOFLON MT Series through-bore slip rings?
Yes. Our engineers can propose an equivalent built around your load, speed and environment. An engineer confirms the fit against your application before recommending anything.
How do I choose the bore size for a through-bore slip ring?
Start with the shaft diameter and its tolerance, then add anything else that must pass through the centre, such as hoses, a rotary union stem or a fibre. Allow clearance for assembly and for the insulating sleeve. Larger bores raise surface speed, cost and drag torque, so pick the smallest bore that genuinely clears what has to pass through.
Can a through-bore slip ring carry Ethernet as well as power?
Yes. Many through-bore units combine power rings with signal rings designed for industrial Ethernet, using controlled impedance, twisted-pair routing and screening between groups. State the protocol and speed, typically 100 Mbit/s or gigabit, so the supplier can allocate suitable rings and keep them away from motor power. For very high data rates, a contactless or fibre channel may be added.
Further reading: How to select a slip ring · Ethernet through slip rings · Slip rings
Other through-bore slip rings series
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Tell us about your project and how you use the MOFLON MT Series through-bore slip rings: the load, speed, duty and environment. An experienced engineer will review it and reply, normally within one working day.
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