How It's Made Season 4 Episode release dates & where to watch

1. Plastic Bottles and Jars, Mail, Eggs, Handcrafted Wooden Pens

Plastic is heated and formed into bottles and jars, letters and parcels are processed through an automated postal facility, eggs are collected, inspected and packaged, and selected woods are turned and finished into handcrafted pens.

2. Plastic Injection Moulds, Automotive Oil Filters, Filing Cabinets, Blown Glass

Precision metal tooling is machined into plastic injection moulds, filter media and metal components are assembled into automotive oil filters, sheet steel is cut and formed into filing cabinets, and molten glass is shaped by hand using traditional glassblowing techniques.

3. High-Precision Cutting Tools, Stained Glass, Semi-Trailers, Recorders

Hard industrial materials are shaped and sharpened into high-precision cutting tools, colored glass is cut and joined into stained-glass panels, structural components are assembled into semi-trailers, and wood or plastic is bored and finished to make recorders.

4. Conga Drums, Metal Plating, Buttons

Wooden staves are joined and fitted with hardware and drumheads to make conga drums, objects receive decorative or protective metallic coatings through electroplating, and a range of materials is molded, drilled and polished into buttons.

5. Grinding Wheels, Compost, Window Blinds, Milk

Abrasive grains and bonding materials are pressed and fired into grinding wheels, organic waste is decomposed and processed into compost, slats and operating mechanisms are assembled into window blinds, and raw milk is tested, pasteurized and packaged.

6. Brushes and Push Brooms, Blackboards, Smoked Salmon, Zippers

Bristles are inserted and secured in handles and blocks to produce brushes and push brooms, smooth writing surfaces are manufactured into blackboards, salmon is cured and smoked, and interlocking teeth are attached to fabric tape to make zippers.

7. 3D Commercial Signs, Hardwood Floors, Corrugated Polyethylene Pipe, Mattresses

Plastic and metal are cut and formed into three-dimensional commercial signs, hardwood is dried, milled and finished into flooring, molten polyethylene is extruded into corrugated pipe, and springs, foam and fabric are assembled into mattresses.

8. Ceramic Tiles, Nuts, Steel Forgings, Skateboards

Clay is pressed, decorated, glazed and fired into ceramic tiles, edible nuts are harvested and prepared for sale, heated steel is shaped under pressure into strong forged components, and laminated wood decks are formed and fitted with skateboard hardware.

9. Car Engines, Flour, Recliners, Envelopes

Machined blocks, pistons and other components are assembled into automobile engines, grain is cleaned and milled into flour, frames and reclining mechanisms are padded and upholstered to make recliners, and paper is cut, folded and glued into envelopes.

10. Plastic Cups and Cutlery, Special Effects Makeup, Gold, Harps

Plastic is thermoformed or molded into disposable cups and cutlery, prosthetics and cosmetics are prepared for special-effects makeup, ore is processed and refined into gold, and carefully selected woods, mechanisms and strings are assembled into harps.

11. Countertop Laminate, Frozen Treats, Children's Building Blocks, Detergents

Decorative paper and resin are layered and pressed into countertop laminate, flavored mixtures are prepared and frozen into treats, plastic is injection-molded into children’s building blocks, and chemical ingredients are blended and packaged as household detergents.

12. Architectural Moldings, Pulleys, Industrial Rubber Hose, Sheet Vinyl Flooring

Wood and composite stock are cut into decorative architectural mouldings, metal components are cast and machined into commercial pulleys, reinforced rubber is built into industrial hose, and multiple layers are formed and printed to make sheet vinyl flooring.

13. Putty Knives, Garage Doors, Electric Motors, Wool Finale

Flexible steel blades are fitted with handles to make putty knives, panels and operating hardware are assembled into garage doors, copper windings and magnetic components are combined into electric motors, and fleece is cleaned, carded and processed into wool fiber.