Shimano CentreLock disc brake nut SM-RT81 - Y8K198010

Q: What is the Y8K198010 nut fr Shimano s used for?

The Y8K198010 nut is used to secure a CenterLock brake disc to the hub . It holds the rotor in place on the hub’s splines.

Q: Is it compatible with the SM-RT81 disc Shimano?

Yes. Part number Y8K198010 is listed on Shimano as a Lock Ring & Washer for the system using the SM-RT81 disc .

Q: What tools are needed to assemble the Y8K198010?

The nut has an internal recess compatible with a cassette removal tool , such as the TL-LR15 Shimano.

Q: Is the washer included?

Yes. The product is supplied as a lock nut/ring with its washer .

Q: What is the tightening torque?

The maximum torque for this bushing is 40 Nm . When fitting, please refer to the guidelines at Shimano that correspond precisely to your setup.

To fit a disc to a wheel

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MPN : Y8K198010 | EAN : 4524667956259 | Ref : 18804440001

€10.50

Price : €16.99

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Based on 4 reviews

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Shimano CentreLock disc brake nut SM-RT81 - Y8K198010

More details In stock

Shimano CentreLock disc brake nut SM-RT81 - Y8K198010

€10.50

Our advice

Bruno V.

Road specialist

Shimano ’s CenterLock SM-RT81 clamping nut, part number Y8K198010, is a replacement part designed to secure Shimano brake discs fitted with the CenterLock system. It secures the disc firmly to the hub via an internal clamping system and is the ideal solution for replacing a lost, damaged or worn nut.

Made from aluminium, this Shimano clamping nut is supplied with a washer and has a black finish. Part number Y8K198010 corresponds to the ‘Lock Ring & Washer’ assembly identified in the Shimano documentation.

A Shimano nut designed for the CenterLock system

The Shimano CentreLock system allows a brake disc to be quickly secured to a compatible hub. Unlike a 6-hole disc, the CentreLock rotor is positioned over central splines and then held in place by a lock ring.

Part number Y8K198010 features an internal spline and is fitted using a cassette removal tool, such as the Shimano TL-LR15. This design allows you to use a tool already available in the workshop for drivetrain and brake maintenance.

Shimano SM-RT81 Compatibility

This clamping nut is specifically listed for the Shimano SM-RT81 CenterLock disc. The documentation at Shimano confirms part number Y8K198010 as the disc mounting part, with compatibility also documented for several Shimano braking systems using the SM-RT81 rotor.

It is particularly suitable for set-ups fitted with a quick-release mechanism or a 12 mm thru-axle, with an internal tool mount.

Technical specifications

Brand: Shimano
Manufacturer’s part number: Y8K198010
Related part number: SM-RT81
Type: CentreLock nut / clamping ring
Application: brake disc mounting
Mounting: CentreLock
Clamping type: internal
Material: aluminium
Colour: black
Grooves: internal
Installation tool: cassette removal tool / Shimano TL-LR15
Recommended tightening torque: up to 40 Nm according to the available technical data sheets
Supplied with: washer
EAN: 4524667956259

Colours	black
EAN	4524667956259
Supplier reference	Y8K198010

Average rating: 5 out of 5

Based on 4 reviews

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Rated 5 out of 5 Ludovic D.

Published Jun 14, 2026 at 07:35 pm Order date: Jun 03, 2026 (Translated review)

Very good
Rated 5 out of 5 Pierre C.

Published Jan 26, 2026 at 10:02 pm Order date: Jan 15, 2026 (Translated review)

Impeccable
Rated 5 out of 5 Michel R.

Published Apr 11, 2025 at 07:55 am (Translated review)

One tool to mount a cassette and tighten a disc by centetlock ...was my choice ...I recommend...the simplicity in use is important
Rated 5 out of 5 Stéphane T.

Published May 26, 2024 at 08:29 pm (Translated review)

No tinkering, sturdier than some brands that copy.

The Y8K198010 nut is used to secure a CenterLock brake disc to the hub. It holds the rotor in place on the hub’s splines.

Yes. Part number Y8K198010 is listed on Shimano as a Lock Ring & Washer for the system using the SM-RT81 disc.

You’ll need to check which type of bushing is required for your hub. The Y8K198010 is an internal-groove model. Shimano also offers external-clamping bushings for certain set-ups.