Only Tencent and Facebook are Core tech companies here that are also involved now in manufacturing via Facebooks’ Express Wifi and Tencents Investment in Ecommerce firs who have manufacturing process, 8 out of 10 are Manufacturing and Tech hybrids, you should change your topic to Manufacturing-Tech hybrids.
Apple: Phones, Tablets, Dockets, TV, Routers, Headphones
Alphabet: Googles Self Driving Cars, Submarine Cable and Internet Lab, Google X Labs, Nest Thermo regulators, Smart blenders etc.
Microsoft: Tablets, Phones, Laptops, Servers etc.
Amazon: Echo and other Smart AI products.
Berkshire Hathaway; GEICO, BNSF, Lubrizol, Dairy Queen, Fruit of the Loom, Helzberg Diamonds, FlightSafety International, and NetJets, and also owns 26% of the Kraft Heinz Company,[ an undisclosed percentage of Mars, Incorporated, and significant minority holdings in American Express, The Coca-Cola Company, Wells Fargo, IBM and Restaurant Brands International.
Exxon Mobil: Oil and Oil Technologies including Seismic 3D Radars who Geologist and Geophysicist have adapted for other uses than oil.
Johnson and Johnson: Baby Care, Skin & Hair Care, Wound Care and Topicals, Oral Health Care,Women’s Health
McNeil Consumer Healthcare, Over-The-Counter Medicines, Nutritionals
Tencent: Media, Games, Entertainment, Ecommerce, Tech.
General Electric: Multi divisions.