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Replacement Floor Scrubber Disc Brushes: How to Identify Size, Drive Plate and Fill

Buying guide · 7 min read · updated 2026-11-02

A worn scrubber brush is one of the most common reorders in floor care, and also one of the most common wrong orders: the diameter looks right but the drive plate doesn't lock onto the machine, or the fill is too aggressive for the floor.

This guide walks through the four things that decide whether a replacement disc brush fits and works: the machine and deck, the brush dimensions, the drive plate and the fill.

1. Start with the machine and the deck

The machine's brand, model and cleaning path are the fastest way to the right brush. The cleaning path is not always the brush size: a deck may run one large disc or two smaller ones side by side, so the brush diameter is often about half the cleaning path on two-brush decks. If the old brush or its part number is available, use it — part numbers on the brush plate are the most reliable reference.

Our replacement brushes by machine pages list brush positions, sizes and OEM part numbers for common scrubbers, including Tennant, Nilfisk, Kärcher, Advance and Clarke models.

2. Measure the old brush

  • Outer diameter of the plate (block) and the outer diameter across the bristle tips — suppliers quote either, so say which you measured.
  • Trim length: how far the bristles stand out of the plate. Worn brushes are shorter than new ones; measure where the fill is least worn or give the original figure.
  • Plate thickness and the height of the hub on top, which affects whether the brush clears the deck.

3. Identify the drive plate (clutch)

The plate on top of the brush is what locks it to the machine's drive, and it is the part most often got wrong. Common types are a moulded or metal clutch plate with lugs or slots that twist-locks onto the drive, a centre hub that bolts or clips on, and quick-change plates specific to one machine family. The same diameter brush can come with different plates for different machines.

The safest way to match it is a clear photo of the top of the old brush, straight on and at an angle, plus the machine model. Our replacement brushes are built on the plate for your machine — see for example the disc brush for Tennant floor machines or the disc scrub brush for Nilfisk BR / SC / BA scrubbers.

4. Choose the fill

From our range: the PP disc scrub brush is made in 12–21 in plate sizes with 0.5–0.6 mm filament and a 43 mm standard trim, and the abrasive filament disc brush comes in 46 or 60 grit silicon carbide or aluminium oxide.

FillTypical useNotes
Polypropylene (PP)Daily scrubbing of most hard floorsEconomical, good in water; the standard fill
NylonDaily scrubbing where longer life mattersBetter bend recovery and wear life than PP; see [nylon vs polypropylene](/guides/nylon-vs-polypropylene-scrub-brush)
Abrasive grit nylonHeavy soil, grouted tile, textured and concrete floorsCuts with grit; check it is suitable for the floor finish
Steel wire or mixedVery heavy soil on rough concreteAggressive; not for coated or polished floors

5. Brush or pad driver?

A disc brush scrubs textured, grouted and uneven floors that a flat pad rides over. On smooth, sealed floors many operators use a pad driver with a floor pad instead, so the pad can be changed for different jobs. The comparison is covered in scrub brush vs pad driver and, for deck types, disc vs cylindrical scrubber brushes.

What to send for a quotation

  • Machine brand and model, and the part number on the old brush if visible.
  • Brush diameter (say whether plate or bristle-tip), trim length and quantity per machine.
  • Photos of the top of the brush showing the drive plate.
  • Floor type and soil, so the fill can be recommended. Send it via Request a Quote.

Frequently asked questions

Is the brush size the same as the scrubber's cleaning path?
Not always. Single-brush decks use a brush close to the cleaning path, but two-brush decks use two smaller brushes side by side. Check the machine model or measure the old brush.
Why doesn't a brush with the right diameter fit my machine?
Usually because the drive plate is different. Brushes of the same diameter are made with different clutch plates or hubs for different machines; match the plate, not just the size.
Polypropylene or nylon for a scrubber brush?
Polypropylene is the economical standard for daily scrubbing; nylon recovers its shape better and usually lasts longer in heavy daily use.
When should I use an abrasive grit brush?
For heavy soil, grout lines and textured or concrete floors that a standard brush doesn't clean. Check the floor finish first, because grit can dull coated or polished floors.

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Need help choosing or a custom spec?

Send us your machine, drawing or requirement — we'll match the right brush and quote, usually within one business day.