Bearings

Most commonly used:

• 608

Fans

Naming convention: $side_width_in_mm$thickness_in_mm

For example:

• 4010 – 40mm x 40mm x 10mm (i.e. 3D printer parts, Sunlu Dryer)
• 4020 – 40mm x 40mm x 20mm (i.e. 3D printer parts)

Magnets

Dimensions: diameter x width

Most commonly used (spherical):

• 6mm x 2mm (Gridfinity)
• 5mm x 2mm (OpenForge)
• 4mm x 2mm (OpenForge)

Screws

Most commonly used:

• M2 – metric 2mm diameter
• M2.5 – metric 2.5mm diameter
• M3 – metric 3mm diameter
• M4 – metric 4mm diameter