Mundane, low-tech components in high-tech items

I’m sure there must be a lot of this sort of thing about, but I can’t think of any specific examples; what I’m looking for is cases where a hugely-expensive and highly-engineered item (such as a jet fighter plane or a combine harvester something) includes, as standard, some inexplicably low-tech component (such as, I dunno, the seat of a plastic stacking chair, like this one.

Or in other words, examples of items where a lot of components had to be very carefully custom-designed, at great expense, but for some reason, the designers just decided to bodge something cheap and common onto it.

Off the top of my head, I can’t think of any examples, but I should point out that not re-inventing the wheel is usually a very good idea. Also if it is stupid, but it works it is not stupid (from Murphy’s laws of combat).

The one that got me was when matt_mcl explained that the brake shoes on Montreal metro trains are made of not some exotic sintered composite or something, but wood.

The floorboards on late 90s model Corvettes are balsa wood. The most advanced fighter planes of the Soviet Union still had vacuum tubes in them.

The hugely expensive and highly engineered power and telecommunications grid for this great nation is held up off the ground by large tree trunks with the limbs lopped off. That’s always blows me away, whenever I think about it.

Wasn’t this to shield them from an EMP from a nuclear bomb?

Clocks in many computers run off a cheap quartz crystal.

…that does a worse job of keeping time than a freebie toy watch from a box of cereal.

Wire is pretty mundane, but there’s a whole lot of it in just about every high-tech device.

Concrete shows up in places you might not expect it. Our computerized front-load clothes washer had a big honkin’ lump of concrete as a stabilizer and/or counterbalance, and Sony lays in a big slab of the stuff in the back end of their big-screen CRT TVs so they don’t flop over face down because 95% of the TV’s weight is in the first inch or so of the CRT’s glass front.

Nope. Our engineers laughed like hell when they first saw the tubes, then they realized it meant that the Soviets could fly after an EMP. At that point we began developing hardened electronics.

I have a pretty wide knowledge of aerospace stuff, so…

-The crews of the B-2 bomber carry a cheap, folding, lawn chair to have a place to take a nap, it´s not a factory option but the particular model they use fits perfectly on the space behind the seats.

-The insulation on the Arianne rockets shroud is made of… cork.

-I don´t recall the name of the current russian space suit, but to seal the suit you grab the inner suit fabric around the opening, wring it and tie a knot.

-The Harrier jump jet was extremely difficult to fly until the installed a small, simple wind vane on top of the nose to help the pilot know there the wind is coming from.