An item fitting inside a dishwasher does not mean it can tolerate heat, alkaline detergent, and pressurized spray. Manufacturer guidance is the authority, but some categories commonly need hand washing: wood, fine knives, decorated pieces, certain reactive metals, and items containing adhesives or electronics.
Look for the manufacturer’s dishwasher guidance
For newer items, check the base, packaging, or manual. A dishwasher-safe label may include top-rack or temperature limits that matter for plastics and bonded parts.
Wood, cast iron, and fine knives usually belong in hand washing
Wood can swell and crack, cast iron can lose seasoning and rust, and detergent plus rack contact can damage good knife edges. Wash and dry these items according to their specific care needs.
Be cautious with aluminum, copper, and decorative finishes
Some metals discolor or react with alkaline detergents, and decorations can fade. If an item is valuable, anodized, painted, or has unclear care instructions, hand washing is the cautious choice.
Never wash electrical or unsealed components
Blender bases, electronics-containing drinkware, electric knives, and parts with unsealed cavities can retain water or be damaged. Wash only removable components specifically identified as dishwasher-safe.