EspressoFit

IMS B70 Competition 1 Cup H18.5 (B701TH18.5N)

verified · 21 August 2026
Border Ø 70mmTamper Ø 58mm18.5mmBody Ø 60mm
Cross-section to scale, from the dimensions IMS publishes for this basket. The border is what seats in the portafilter — not the tamper figure the size is usually quoted by. See why “58mm” isn’t one standard.

That model name is an IMS product code — series, cup count, height and hole pattern are all encoded in it. IMS basket codes, decoded explains how to read one, and lists every code covered here.

This basket is one of a line. See every IMS B70 Competition basket compared — the whole ladder of heights and variants on one page, with the three diameters they share.

Fits these machines

The shallowest basket in IMS’s B70 line at 18.5mm — a genuine single-shot basket rated 6–8 g for a dark roast and 8–10 g for a light one. There is nothing smaller in the series.

Truncated cone, and ridgeless

This is not simply a shorter version of the taller B70 singles. IMS gives its shape as a truncated cone and its ridge as Ridgeless, and explains the reason in its own words: the taper ‘exploits the whole coffee puck even with lower quantities, facilitating drying and expulsion’. A thin dose in a straight-walled basket spreads out into a shallow, fragile puck; narrowing the floor keeps the bed deep enough to hold resistance.

Ridgeless means the retaining spring has no lip to grip. That is a good match for a bottomless portafilter and worth knowing about if you use a spouted one — IMS’s ridged M-pattern doubles are the line with an external Ø60.5mm ridge.

The two truncated-cone singles

Code Height Dark Medium Light
B701TH18.5N 18.5mm 6/8 g 7/9 g 8/10 g
B701TH19.5N 19.5mm 7/9 g 8/10 g 9/11 g

Both share the same perforation — 177 holes of 0.30mm in the Normal pattern over a Ø30mm face, each hole circular with a conical cross-section so flow accelerates on the way out. One millimetre of height is worth about a gram of dose.

If you want more than 10 g in a single basket, the taller H24.5 and H26.5 singles use a different approach — a specific curvature radius rather than a cone — to build a taller puck.

Standard B70 fitment otherwise: La Marzocco, Rancilio, Lelit, Rocket, ECM and the Breville Oracle. Gaggia is B68, not B70.

Find the IMS B70 Competition 1 Cup H18.5 (B701TH18.5N) on Amazon (affiliate link — see our disclosure)

Also fits the same machines

Other items confirmed to fit machines this one fits — useful if you're kitting out a single setup. The count is how many of those machines overlap; nothing here is a new fitment claim.

FAQ

What size portafilter is the IMS B70 Competition 1 Cup H18.5 (B701TH18.5N) for?
It is a 58mm basket, 18.5mm deep, for 58mm portafilters.
Is the IMS B70 Competition 1 Cup H18.5 (B701TH18.5N) pressurized?
No — it is a non-pressurized (single-wall) basket, for freshly ground coffee.
Does the IMS B70 Competition 1 Cup H18.5 (B701TH18.5N) fit 54mm machines like the Breville Barista Express?
No. It is a 58mm basket, so it does not fit Breville's 54mm machines or any 54mm portafilter.
Which machines does the IMS B70 Competition 1 Cup H18.5 (B701TH18.5N) fit?
Breville Oracle; ECM Estetika; ECM Mechanika MAX II; Flair 58; La Marzocco GS3; La Marzocco Linea Micra; La Marzocco Linea Mini; Lelit Bianca (PL162T); Lelit Elizabeth (PL92T); Lelit Kate (PL82T); Lelit MaraX (PL62X); Lelit Victoria (PL91T); Rancilio Silvia; Rancilio Silvia Pro; Rancilio Silvia Pro X; Rocket Espresso Appartamento; Rocket Espresso Epica; Rocket Espresso Giotto Fast; Rocket Espresso Mozzafiato Fast; Rocket Espresso Porta Via; Rocket Espresso R Nine One — each confirmed against manufacturer sources (listed below).

Sources

Spot an error? The fastest fix is the source itself —send us the manufacturer page that contradicts this entry and we'll correct it and cite it. See how we verify.