Fit sheetBreville Bambino

Breville Bambino Portafilter, Basket and Tamper Fit Guide

Q: Will a 54 mm tamper fit the Bambino?

Breville supplies the Bambino with a 54 mm tamper, so a tamper sold at that size is what the machine is designed around. What a tamper actually has to fit is the basket's inner diameter, which Breville does not publish, and aftermarket tampers for this group are made in slightly different base sizes. If one binds on the basket wall or leaves loose coffee around the edge, measure the basket and choose a base just smaller than it.

Q: Can I use a bottomless portafilter on the Bambino?

Only one made for Breville's 54 mm group and listed for the Bambino by model, because the locking lugs have to match as well as the size. Use it with a single-wall basket: a bottomless portafilter is meant to show the coffee flowing from the base of the basket, and a pressurized basket's single exit hole defeats that.

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Short answerThe Breville Bambino takes a 54 mm [1] portafilter and comes with a 54 mm [1] tamper. Breville does not publish the inner diameter of its baskets.

Last verified: 2026-09-25Manufacturer page: Breville Bambino on breville.com

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Sizes for Breville Bambino

Portafilter size: 54 mm [1]
Basket inner diameter: Not found in the manufacturer documents checked
Manufacturer's tamper: 54 mm [1]
Group gasket (outer × inner × thickness): Not found in the manufacturer documents checked

[1] Breville the Bambino BES450 Instruction Book (US/Canada/Mexico, PDF), retrieved 2026-09-25

Specs

Sources (1)

Breville Bambino: accessory fit specs
Part	Spec	Value
Portafilter	Nominal sizeAluminum, per Breville's instruction book	54 mm [1]
Filter basket	Inner diameter	Not found in the manufacturer documents checked
Filter basket	Baskets supplied	Single wall and dual wall filter baskets, 1 cup and 2 cup [1]
Tamper	Size of the tamper supplied	54 mm [1]
Group gasket	Outer diameter	Not found in the manufacturer documents checked
Group gasket	Inner diameter	Not found in the manufacturer documents checked
Group gasket	Thickness	Not found in the manufacturer documents checked
Shower screen	Diameter	Not found in the manufacturer documents checked

Checking your own parts? How to measure a filter basket and tamper.

About this fit sheet

The Bambino (model BES450) is Breville's compact machine without a built-in grinder. Most accessory questions about it come down to three things in the table: the nominal portafilter size, which tells you which portafilters and belong to its group; the baskets Breville supplies, which tell you whether you are brewing with or baskets; and the that comes in the box.

Breville's instruction book gives the portafilter and tamper sizes but not the basket's inner diameter, the group gasket's dimensions or the shower screen's diameter, so those rows say so. The basket's inner diameter is the figure that decides whether an aftermarket tamper or distribution tool fits, so if you need it, measure your own basket. The Bambino Plus (BES500) is a separate model with its own entry in the checker.

Questions

Will a 54 mm tamper fit the Bambino?

Breville supplies the Bambino with a 54 mm [1] tamper, so a tamper sold at that size is what the machine is designed around. What a tamper actually has to fit is the basket's inner diameter, which Breville does not publish, and aftermarket tampers for this group are made in slightly different base sizes. If one binds on the basket wall or leaves loose coffee around the edge, measure the basket and choose a base just smaller than it.

Are the Bambino's baskets pressurized?

It comes with both kinds: Single wall and dual wall filter baskets, 1 cup and 2 cup [1]. The dual-wall baskets are pressurized, with one small exit hole underneath, and are the forgiving choice for pre-ground coffee. The single-wall baskets have holes across the whole base, so the grind and the tamp have to create the resistance.

Can I use a bottomless portafilter on the Bambino?

Only one made for Breville's 54 mm [1] group and listed for the Bambino by model, because the locking lugs have to match as well as the size. Use it with a single-wall basket: a bottomless portafilter is meant to show the coffee flowing from the base of the basket, and a pressurized basket's single exit hole defeats that.

Do Barista Express portafilters and baskets fit the Bambino?

Breville's instruction books give both machines the same nominal portafilter size (the checker cites each one), so their baskets belong to the same size group. Breville does not publish basket inner diameters for either machine or state that their portafilters interchange, so buy a portafilter listed for the Bambino by model.

What group gasket and shower screen does the Bambino take?

Breville does not publish the gasket's outer diameter, inner diameter or thickness, or the shower screen's diameter, in the documents checked. Order replacements listed for the BES450 by model number instead of measuring the old gasket: a used gasket is compressed and reads thinner than a new one.

Sources

[1]Breville the Bambino BES450 Instruction Book (US/Canada/Mexico, PDF), assets.breville.com.Retrieved 2026-09-25

Last verified: 2026-09-25

Terms used

portafilter: The handled holder that carries the filter basket and locks into the machine's group head. Manufacturers quote a nominal portafilter size, which names the group it fits. The locking lugs (ears) must match the group too, so an aftermarket portafilter should be listed for your machine model, not only for the same size.
filter basket: The perforated metal cup that sits in the portafilter and holds the coffee. Two diameters matter: the outer rim, which has to suit the portafilter, and the inner diameter, which sets the size of tamper and distribution tool that will fit. Baskets are either single-wall (non-pressurized) or dual-wall (pressurized), and come in single and double sizes.
tamper: A hand tool for pressing ground coffee into the filter basket. Tampers are sized by the diameter of the base, which has to be slightly smaller than the basket's inner diameter: a base as wide as the basket won't go in, and one much narrower leaves loose coffee around the edge.
pressurized basket: A dual-wall filter basket. The inner wall is perforated, but coffee leaves through one small hole in the outer wall, and that restriction builds pressure even when the grind or tamp is uneven. That makes it forgiving with pre-ground coffee. Turn the basket over to tell: one small exit hole instead of a field of holes.
non-pressurized basket: A single-wall filter basket with many small holes across its base. The resistance that builds brewing pressure comes from the coffee itself, so grind size, dose and tamping all change the shot. Also called a standard or single-wall basket. Bottomless portafilters are made for this type.
bottomless portafilter: A portafilter with the underside cut away and no spouts, so the base of the filter basket is exposed and espresso runs straight from the basket into the cup. It is made for single-wall (non-pressurized) baskets. Like any portafilter, its locking lugs have to match the machine's group, so check that it is listed for your model and not just for the same nominal size.