The nut that does not loosen by itself
An espresso machine vibrates. The pump runs, the group closes, the portafilter is locked in – a hundred times a day. Under these knocks an ordinary nut slowly works itself loose over months, a self-locking one does not: its locking element keeps the thread under permanent tension.
La Marzocco lists this nut as a self-locking hex nut M5 with AF 8 and a height of 5 mm under part number I.3.016. It is a typical small part that is needed individually during a service – and is missing exactly then.
When it is due
The old nut suddenly turns easily as you screw it on – then its locking element has lost its effect and it needs replacing, not reusing. It got lost during disassembly. Or you are overhauling an assembly and want to have the small parts ready beforehand.
At a glance
| Type |
Hex nut M5, self-locking |
| Location |
Listed in the spare parts list without a fixed location |
| Fits |
La Marzocco machines in which this number is fitted |
| Scope of delivery |
One nut |
| Part number |
I.3.016 |
| Version |
AF 8, height 5 mm |
| Brand |
La Marzocco |
Who it is for
For service companies that always replace the self-locking nuts when they disassemble an assembly, and for technically skilled owners who pick up the matching small parts at the same time when ordering larger parts.
What goes with it
From the same drawer come the M6 × 10 pan head screw, the M6 × 18 hex head screw, the M3 × 12 screw and the M5 nut for the conical paddle valve of the GS3. Everything for the brand under La Marzocco accessories and spare parts.
Workshop tip from Bern and Zurich
This is our routine, not a manufacturer requirement: we only ever fit self-locking nuts once. Anyone who uses them twice saves 55 centimes and ends up driving back to the customer three months later. With it, an espresso made with Very Nutty when the small-parts work takes longer. More under Coffee beans.
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 trial fitting on the machine. So before ordering, check the model, year of manufacture and serial number of your machine – or drop us a line and we will clarify the fit together. Your rights in the case of defective goods remain unaffected.
Frequently asked questions
Where exactly does this nut sit?
The spare parts list gives no fixed location for it, and we are not going to make one up. If you have the number I.3.016 from an exploded view, it fits. If in doubt, send us the model and serial number.
Do I get one nut or a set?
One nut is supplied. If you need several, enter the quantity in the shopping cart.
Can I use a nut from the hardware store?
M5 is a standard size, but on an espresso machine the material and height matter. This item is the original part with AF 8 and a height of 5 mm – exactly the dimensions that make the difference in a tight assembly.
May I reuse the old nut?
No, we advise against it. The locking element of a self-locking nut works best the first time it is fitted and loses holding force after that.
Can I pick up the part from your showroom?
Yes. We have two locations: Bern at Gerberngasse 44 and Zurich at Hagenholzstrasse 50b. Drop us a line and we will have it ready for you.
Questions about the fit? Write to us at [email protected]. We deliver across Switzerland and to Liechtenstein in 2-4 working days.
