How It's Made Season 21 Episode release dates & where to watch

1. Rubber Gloves, Soap Carvings, Aircraft Cabinets, Motorcycle Brake Locks

Ceramic hand forms are coated with liquid rubber, cured and stripped to produce flexible protective gloves. Blocks of soap are cut and sculpted into intricate decorative figures; lightweight panels, veneers and hardware are assembled into cabinets for aircraft interiors; and hardened metal components are fitted with locking mechanisms to create motorcycle brake locks.

2. Powder Horns, Handcrafted Molds, Pierogi, Inner Tubes

Animal horns are cleaned, heated, shaped and polished before being fitted with plugs and pouring spouts for use as traditional powder horns. Craftspeople produce precision moulds for decorative glassware; rounds of dough are folded around savoury fillings to make pierogies; and rubber tubing is extruded, joined, fitted with valves and vulcanized into tire inner tubes.

3. Lace, Antique Frame Replicas, Orchids, Unicycle Wheel Hubs

Thousands of threads are guided through specialised machinery to create complex lace patterns. Ornamental profiles are reproduced, joined and finished as replicas of antique picture frames; orchids are propagated and cultivated under carefully controlled greenhouse conditions; and metal blanks are machined and drilled into hubs for unicycle wheels.

4. External Hard Drives, Frozen Shrimp, Thai Rice Boxes, Paper Towels

Disk drives, control electronics and connection ports are installed inside protective enclosures to make external hard drives. Shrimp are sorted, cleaned, peeled and rapidly frozen; thin strips of bamboo are prepared and woven into traditional Thai rice boxes; and absorbent paper is formed, embossed, perforated and wound into rolls of paper towels.

5. Tea, Roof Finials, Artificial Flowers, Alloy Wheels

Fresh tea leaves are picked, withered, rolled, oxidized and dried to develop their flavour and aroma. Decorative roof finials are shaped and finished to withstand the weather; fabric petals and leaves are cut, coloured and assembled into artificial flowers; and molten alloy is cast, machined and coated to produce lightweight vehicle wheels.

6. Gel Caps, Playground Spring Riders, Frozen Pancakes, Natural Rubber

Gelatin is prepared and formed into matching capsule halves before the finished gel caps are inspected and packaged. Moulded figures are mounted on heavy coil springs to create playground riders; batter is portioned, cooked, cooled and frozen into ready-to-heat pancakes; and latex collected from rubber trees is coagulated, rolled and dried into natural rubber.

7. Paper Umbrellas, Coal, Aircraft Seats, Cremation Urns

Slender bamboo pieces are joined into folding frames and covered with decorated paper to make traditional umbrellas. Coal is excavated, transported, crushed and sorted; lightweight frames, padding and upholstery are assembled and tested as aircraft seats; and carefully shaped vessels are finished and decorated as cremation urns.

8. Aluminum Canoes, Wooden Stave Bowls, Wheelchair Accessible Vans, Marimbas

Sheets of aluminum are formed and joined around supporting ribs to create lightweight canoes. Angled wooden staves are glued into hollow forms and turned into bowls; vans receive lowered floors, ramps and other accessibility equipment; and carefully selected wooden bars are cut, tuned and mounted above resonators to produce marimbas.

9. Indy Car Seats, Paper Flowers, Stand-by Generators

A racing driver’s body is measured and moulded to create a closely fitted seat that provides support and protection inside an Indy car. Paper is cut, coloured and shaped into realistic flowers, while engines, alternators, control systems and protective housings are assembled and tested as standby generators.

10. Customized Knee Replacements, Leaf Springs, Lavender Essential Oil, Rivets and Rivet Tools

Medical scans and computer models guide the production of customized knee-replacement components designed for an individual patient. Steel strips are cut, heat-treated and curved into vehicle leaf springs; harvested lavender is steam-distilled to extract its essential oil; and metal blanks are formed into rivets alongside the tools used to install them.

11. Cast Iron Stoves, Ultralight Aircraft, Snow Groomers, Rubber Bands

Molten iron is poured into moulds, cleaned and finished before the heavy castings are assembled into wood-burning stoves. Lightweight structural components are joined into ultralight aircraft; tracked chassis, hydraulic systems and grooming equipment are combined into machines that maintain snow-covered trails; and cured rubber tubes are sliced into individual rubber bands.

12. Barber Chairs, Sewage Pumps, Bimini Boat Tops, Diesel Filters

Steel frames, hydraulic lifting mechanisms, padding and upholstery are assembled into adjustable barber chairs. Motors and impellers are enclosed in corrosion-resistant housings to create sewage pumps; marine fabric is measured and sewn to fit folding frames for Bimini boat tops; and porous filter elements are enclosed in steel housings to remove soot from diesel exhaust.

13. Car Tires, Silk, Art Conservation, Scuba Tanks Finale

Different rubber compounds are mixed and assembled with reinforcing fabric, steel belts and tread before being moulded and vulcanized into car tires. Fine filaments are unwound from silkworm cocoons and combined into thread; conservators clean, stabilize and repair ageing works of art; and high-pressure metal cylinders are formed, heat-treated and tested to produce scuba tanks.