McMetric

Metric equivalents next to imperial measurements on McMaster-Carr, plus dark and beige themes.

Tired of mentally converting inches while browsing McMaster-Carr? McMetric annotates every imperial measurement with its metric equivalent, inline and in green, so 3/4" reads 3/4" (19.05 mm). What gets converted: • Inches (fractions, mixed numbers, decimals) → mm or m • Feet → m • Pounds → kg, or Newtons when the context is a load/force rating • lbf → N • Ounces → g • psi → bar, or MPa for tensile strengths • °F → °C Works everywhere on mcmaster.com: product detail pages, catalog listing tables (including columns whose unit lives in the header, like "Working Load, lb."), and sidebar filters. Thread callouts like 1/4"-20 are left untouched — they're size designations, not dimensions. Toggle annotations on or off from the toolbar popup. No accounts, no tracking, no data collection. Runs only on mcmaster.com. V1.2: torque and drill-gauge conversions, per-unit preferences pane V1.7.1: themes added: dark mode and beige mode, bug fixes V1.8.1: improved dark theme, spring rate & No. # screw conversions, bug fixes