Polisher type
15 mm long-throw polishers: the 5-inch class
15 mm random orbital polishers usually run a 125 mm (5 in) plate: RUPES LHR15ES, Milwaukee 2684-20, FLEX XFE 15. Speeds, plates and limits.
Also listed as 15mm polisher, 5 inch long throw
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Short answer
A 15 mm long-throw polisher is a free-spinning random orbital machine, usually with a 125 mm (5-inch) plate: RUPES's LHR15ES (corded), Milwaukee's M18 2684-20 and FLEX's XFE 15 (cordless). RUPES says its 15 mm machine runs at a higher rpm than its 21 mm one for equivalent cutting power, a maker claim. ESOTERIC Car Care, a RUPES retailer, calls 15 mm machines more versatile on curves and in tight spaces.
What fits
- 15 mm corded random orbital polisherFLEX FC3321‑Z 120 V brushless random orbital polisher (15 mm)Check price on Amazon
- 15 mm cordless random orbital polisher (FLEX 24V)FLEX FX3321‑Z 24V brushless cordless random orbital polisher, 15 mm (tool only)Check price on Amazon
Key facts
- Backing plate / pad size
- 125 mm / 5 in (RUPES LHR15ES); Milwaukee 2684-20: 5 in recommended, 6 in optional[1][4]
- Power source
- Corded (RUPES LHR15ES, 500 W) or cordless (Milwaukee M18; FLEX 18 V)[1][2][3]RUPES's page states no supply voltage.
- Example models
- RUPES BigFoot LHR15ES; Milwaukee M18 FUEL 2684-20; FLEX XFE 15 150 18-EC (US kit 459542)[1][2][3]
- Suited to
- ESOTERIC Car Care: more versatile for curved areas and tight spaces[5]A retailer's practical opinion, not a measurement.
- Cautions
- Too much pressure, the wrong angle or improper motion may cause swirl marks or burning[4]Milwaukee's polisher manual warning, written for its random orbital polishers.
Watch out for
- 21 mm is not automatically stronger. RUPES claims its 15 mm LHR15ES matches the LHR21ES's cutting power by running at a higher rpm. That is a maker claim, not an independent test.
- Bare tools have no battery. Milwaukee's -20 suffix is the bare tool; it runs on genuine M18 REDLITHIUM packs only.
- Pad overhang is a maker choice. RUPES pairs a 125 mm plate with 130-150 mm foam pads; Milwaukee says plate and pad diameters should match on its polishers.
- Voltage is not on RUPES's page. RUPES's global page states no supply voltage, so check a US 120 V version before buying.
What fits
Product details below are the seller's own description unless a source is shown. Pick the variant named for each item.
15 mm corded random orbital polisher
FLEX FC3321‑Z 120 V brushless random orbital polisher (15 mm)Choose the FC3321-Z listing that includes the 5 in (FT333) and 6 in (FT334) backing plates.
Sold on Amazon: check 'Ships from' and 'Sold by' on the Amazon offer before you buy, and look for a North American certification mark on the tool's nameplate.
Check price on Amazon15 mm cordless random orbital polisher (FLEX 24V)
FLEX FX3321‑Z 24V brushless cordless random orbital polisher, 15 mm (tool only)Choose the FX3321-Z tool-only listing; battery and charger are sold separately.
It runs on FLEX 24V packs, so pair it with genuine FLEX batteries and a FLEX charger. As with any Amazon pick, check 'Ships from' and 'Sold by' on the Amazon offer before you buy.
Check price on Amazon
Next size up: 21 mm long-throw. For the motion itself, see free-spinning dual-action.
Questions
Is a 15 mm or a 21 mm polisher better?
Neither is better for every job. ESOTERIC Car Care, a RUPES retailer, calls 15 mm machines more versatile on curves and in tight spaces and 21 mm machines suited to larger flat panels; RUPES claims equal cutting power at different speeds.[5][1]
Can I fit a 6-inch pad on a 15 mm polisher?
On Milwaukee's 2684-20 the manual lists 5-inch as recommended and 6-inch as optional, with a matching backing plate. Other makers set their own rules, so check your tool's manual.[4]