Steam/Water Knob for Rocket R58/Mozzafiato/Appartamento without Cap
The Rocket knob A639905816 for the steam and hot water valve of the Rocket R58, Mozzafiato and Appartamento. Original spare part, supplied without cap, available in Bern and Zurich.
The knob sits on the outside of the valve spindle and engages via a 7 × 7 mm square fitting. Rocket lists it in the R58 spare parts catalogue as “Steam/hot water valve handle”, there from serial number D1540R58. The valve gaskets are separate items in the catalogue and not part of the knob.
At a glance
| Manufacturer |
Rocket Espresso |
| Part number |
A639905816 |
| Manufacturer name |
Steam/hot water valve handle |
| Fitting |
square 7 × 7 mm (retailer information) |
| Fits |
Rocket R58 from serial number D1540R58 (Rocket spare parts catalogue), Mozzafiato Evoluzione and Appartamento (retailer information) |
| Scope of delivery |
one knob, without cap |
Who it is for
For everyone with a Rocket R58, Mozzafiato Evoluzione or Appartamento whose knob is broken, worn out or scuffed. More parts are under Rocket R58 and R60 spare parts, Rocket Mozzafiato spare parts, Rocket Appartamento spare parts and Rocket accessories and spare parts. Delivery across Switzerland and to Liechtenstein in 2–4 working days.
A steam wand goes with a milk pitcher. For everyone who wants a pitcher that is affordable and precise: Normcore. If you want more: Rhino or Weber Workshops. All three are under barista milk pitchers. Descaler and cleaning products are in machine and grinder cleaning. The machines themselves are in our Rocket Espresso collection, and our advice tool shows which machine suits your setup.
No returns
Original spare parts are excluded from exchange and return. They are sourced specifically for each order and cannot be resold after installation or a test fit on the machine. Please check the model, year of manufacture and serial number of your machine before ordering, or write to us at [email protected]. Your rights in the case of defective goods remain unaffected.
Frequently asked questions
Is a cap included?
No. The knob is supplied without a cap. Caps and other small parts are under Rocket accessories and spare parts.
Does the knob fit my Giotto or Cellini?
The A639905816 is listed for the R58, Mozzafiato Evoluzione and Appartamento. We have no confirmation for other models. If in doubt, send us your model and serial number at [email protected].
My valve drips. Will a new knob help?
No. The knob only transfers the turning movement to the valve spindle. Rocket lists the valve gaskets as separate items in its catalogue.
Can I see the part before buying?
Our showrooms in Bern (Gerberngasse 44) and Zurich (Hagenholzstrasse 50b) show a wide selection, but not our entire range – the display changes. We are happy to check in advance by email at [email protected] whether the spare part is in Bern or in Zurich Oerlikon (Hagenholzstrasse 50b). Click and Collect is possible at both locations.
Tip from the roastery: For milk drinks, Cozy Chocolate and Nutty Delight are a good match. Both are dense, round and chocolatey and hold up well even with a lot of milk. If you want maximum body without acidity, choose Very Nutty. If you want to discover something fruity, you will find it in Wild Peach. That is our recommendation, one of many.
