Blind Acorn Nut

Blind Acorn Nut, M8, Rancilio & Cross-Brand

Blind (acorn-style) hexagonal M8 nut, UNI 5721, used primarily on older Rancilio portafilters but cross-compatible with several other lever and grinder assemblies from other Italian machine brands.

SPECIFICATIONS

• Size: M8 blind hex nut
• Standard: UNI 5721

COMPATIBILITY

• Fits: Older Rancilio portafilters and lever/grinder assemblies, including the Z-9/Z-11 AT/ATS/ATF automatic group portafilter, MD40 grinder (shown as MR_196), MD50/MD80 grinder (position #13), and the S-20 group portafilter; also used on Pavoni lever brew groups (Bar/Bart/Pub/Hotel, group flange bolts) and Promac brew groups (Green/Compact/Club, portafilter)
• Replaces: Rancilio/Promac #37320800, Pavoni #4020177. Now superseded on current Rancilio builds by the R_419 fixing nut

INSTALLATION

Basic hand-tool hardware swap.

PRO TIPS

• If you are restoring an older lever machine, check whether your build uses this blind acorn nut or the newer open-style R_419 fixing nut before ordering, they are not visually identical, and the acorn nut fully caps the stud end.