Assembly Line

Grinding and polishing

Abrasives take off tiny amounts of material, giving a precise dimension or a smooth, reflective surface.

101 lines that use it

Ball bearing 9 stations · 13 raw sources Billiard ball 9 stations · 21 raw sources Bowling ball 8 stations · 23 raw sources Brake pad 7 stations · 23 raw sources Button 8 stations · 8 raw sources Cake mix 6 stations · 20 raw sources Camera lens 6 stations · 10 raw sources Cast iron pan 6 stations · 11 raw sources Cement 7 stations · 3 raw sources Chess set 9 stations · 13 raw sources Chopsticks 6 stations · 10 raw sources Clothespin 7 stations · 12 raw sources Cocoa powder 7 stations · 1 raw source Coil spring 7 stations · 21 raw sources Cricket bat 7 stations · 9 raw sources Cultured pearl 6 stations · 2 raw sources Cut diamond 6 stations · 1 raw source Dartboard 7 stations · 22 raw sources Dice 7 stations · 21 raw sources Die-cast toy car 8 stations · 24 raw sources Drill bit 7 stations · 15 raw sources Drumstick 8 stations · 8 raw sources Eyeglass frame 8 stations · 28 raw sources Eyeglass lens 6 stations · 13 raw sources Eyeshadow 5 stations · 16 raw sources Faucet 11 stations · 23 raw sources Felt hat 8 stations · 10 raw sources Ferrite 6 stations · 6 raw sources Flour 7 stations · 9 raw sources Foundation makeup 6 stations · 24 raw sources Fountain pen 6 stations · 20 raw sources Gold ring 8 stations · 12 raw sources Golf ball 8 stations · 21 raw sources Golf club 10 stations · 27 raw sources Granite 3 stations Granite countertop 6 stations · 1 raw source Hard drive 6 stations · 27 raw sources Harmonica 8 stations · 19 raw sources Hip implant 9 stations · 22 raw sources Ice skates 8 stations · 22 raw sources Incense 5 stations · 3 raw sources Indium tin oxide 7 stations · 15 raw sources Ink 8 stations · 15 raw sources Jet engine 7 stations · 23 raw sources Kitchen knife 6 stations · 16 raw sources Lab-grown diamond 6 stations · 3 raw sources Leather wallet 10 stations · 15 raw sources Lipstick 7 stations · 13 raw sources Marble 3 stations Mascara 6 stations · 13 raw sources Matcha 5 stations · 1 raw source Mayonnaise 6 stations · 19 raw sources MDF 7 stations · 8 raw sources Mechanical wristwatch 6 stations · 26 raw sources Mustard 6 stations · 15 raw sources Nail polish 6 stations · 17 raw sources Nonstick pan 7 stations · 10 raw sources Oak wine barrel 7 stations · 12 raw sources Paint 6 stations · 21 raw sources Paper 7 stations · 7 raw sources Peanut butter 6 stations · 12 raw sources Phenolic resin 5 stations · 5 raw sources Pigment 8 stations · 8 raw sources Plaster of Paris 5 stations · 1 raw source Plywood 6 stations · 8 raw sources Popsicle stick 6 stations · 1 raw source Pressure cooker 8 stations · 18 raw sources Quicklime 6 stations · 2 raw sources Rare earth ore 4 stations Razor blade 6 stations · 16 raw sources Safety pin 9 stations · 21 raw sources Sake 8 stations · 14 raw sources Sanitary pad 7 stations · 10 raw sources Saw blade 7 stations · 17 raw sources Scissors 8 stations · 22 raw sources Screw 7 stations · 13 raw sources Semolina 6 stations · 2 raw sources Sewing needle 8 stations · 16 raw sources Silicon wafer 6 stations · 8 raw sources Ski 8 stations · 24 raw sources Snow globe 9 stations · 26 raw sources Snowboard 10 stations · 23 raw sources Stained glass 10 stations · 24 raw sources Stainless steel fork 8 stations · 15 raw sources Sunglasses 9 stations · 15 raw sources Sunscreen 8 stations · 17 raw sources Surfboard 8 stations · 14 raw sources Tennis racket 9 stations · 25 raw sources Toothbrush 7 stations · 14 raw sources Toothpick 6 stations · 1 raw source Tortilla 7 stations · 12 raw sources Tungsten carbide 5 stations · 11 raw sources Ukulele 9 stations · 11 raw sources White rice 6 stations · 1 raw source Windshield 8 stations · 20 raw sources Wine cork 8 stations · 11 raw sources Wooden chair 6 stations · 21 raw sources Wooden door 6 stations · 11 raw sources Wooden spoon 5 stations · 7 raw sources Wrench 9 stations · 20 raw sources Zinc ore 4 stations

What it looks like on the line

  • FaucetGrind and polish. Grinding takes out the rough cast surface and polishing leaves it flawless. After this, bare hands stay off, because fingerprints would show through the plating.
  • MarblePolish for the finish. Slabs are ground and polished until the crystals reflect light. White marble was prized for sculpture partly because it is soft enough to carve easily.
  • SakePolish away the husk. Sake rice is milled to remove the outer layers, which carry fat and protein that would cause off-flavors. Only the starchy core stays. A polish of 70% means 30% of each grain has been ground away.
  • ScissorsGrind the edges. Grinders cut the sharp edges into the hardened blades. Irregular shapes make this job hard to automate.
  • Eyeglass frameTumble in wood chips. Fronts and temples ride in barrels of beech and birch chips with polishing paste for 48 to 76 hours. Slow abrasion takes off the sharp edges and tool marks.
  • ClothespinTumble them smooth. The jaws tumble together so the sharp edges rub each other round. Some makers add an oil-dampened cloth for a finish.
  • Stained glassClean and polish. Excess cement is cleaned away and the panel is buffed, leaving the lead with a rich patina.
  • PaintLoad and disperse pigment. With the disperser running, titanium dioxide and extenders such as calcite, talc and barytes go in a set order. Blade speed climbs as the load grows, and shear breaks clumps of pigment so resin and additives can wet every particle.
  • Popsicle stickBundle and round the ends. Sticks are packed in tight bundles so a rounding tool can shape the ends of a whole bundle at once.
  • Cast iron panGrind off rough spots. Seams and stubs are ground down. The cooking surface may be machined smoother.
  • LipstickGrind pigment into oil. Pigments and mineral powders are rolled with castor oil or similar oil through steel rollers until no gritty specks remain. A smooth paste means an even color on the lips.
  • Razor bladeGrind the wedge. Abrasive wheels grind both faces of the edge down in stages, until they meet at a fine tip.