The grub screw that clamps without leaving marks
This grub screw is 20 mm long and has a tip made of POM, a tough plastic, at the front. The difference from a bare steel screw is precisely this tip: it presses against the spindle without digging into it. Where a hard screw would have cut a notch into the shaft after the third service, the surface stays smooth here.
That makes it a wear part by design: at some point the plastic tip is flattened and the clamping no longer holds. Then you replace the screw – and not the component behind it.
When it's due
A replacement is needed if the POM tip is visibly flattened or sheared off, if the clamped part slips on the spindle even though the screw is tightened, if the hex socket is rounded out, or if the screw was lost during disassembly.
At a glance
| Type |
Grub screw with hex socket and POM tip, spare part |
| Installation location |
Clamping point on spindles and shafts |
| Fits |
La Marzocco machines with part number I.6.027 – send us the serial number and we'll check the fit |
| Scope of delivery |
one grub screw |
| Part number |
I.6.027, formerly I.4.005 |
| Version |
M5 × 20 mm, POM tip |
| Brand |
La Marzocco |
Who it's for
For service technicians who want to protect a shaft, and for anyone whose control part slips even though the screw is tight.
What goes with it
Good matches are the Grub screw M4 × 6 mm stainless steel and the control parts it holds, such as the Rotary knob KB90 or the Spacer sleeve 3.5 × 1 × 5. Everything else under La Marzocco accessories and spare parts and Original spare parts.
Tip from our workshop
When a knob slips at our place in Bern or Zurich, we don't just tighten it harder – that only shears off the plastic tip faster. We unscrew the screw completely and take a look at it: if the tip is flat, a new one goes in, done. That's our routine, not a manufacturer specification. We like to pull the espresso afterwards with Nutty Delight, Cozy Chocolate for chocolatey notes or Very Nutty for body. All roasts 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'll clarify the fit together. Your rights in the case of defective goods remain unaffected.
Frequently asked questions
What does the POM tip do?
It clamps firmly without digging into the spindle. The shaft stays smooth, and the screw is the wear part.
How many pieces do I get?
One grub screw. If you need several, increase the quantity in the cart.
Is this the same as I.4.005?
Yes. Number I.6.027 has replaced the former number I.4.005.
My knob still slips with a new screw – what now?
Then the spindle is usually worn or the thread in the component is damaged. Write to us and we'll look at it together.
Can I see the part in the showroom?
Yes, you can see it in person in Bern (Gerberngasse 44) and Zurich (Hagenholzstrasse 50b).
Questions? Write to [email protected]. Delivery across Switzerland and to Liechtenstein in 2-4 working days.
