20 'Hidden' Features Of Everyday Things Explained

There are certain designs that we're so used to, we hardly ever question why they're created that way. You know, like the ridges on the sides of coins or the fluffy pom-poms on winter beanies. Well, these subtle design quirks are actually there for a reason and had served a purpose back in the day. Some of actually still do even to this day - and I'm pretty sure they'll leave you pleasantly surprised. Check out some interesting features 'hidden' in the things many of us use every day in the gallery below! And if you love secrets and hidden things, see our previous posts here and here.

#1 Half-belts

Image source: Fuchsia Back in the day, some military jackets used to double as blankets and the half-belt helped keep the extra material from getting into the soldiers' way. Nowadays they're mostly used as a fashion accessory.

#2 Notebook margins

Image source: Jason Staten As fun as it may be too doodle in the margins of a notebook during a boring lecture, that's not the original reason why they're there. Back in the old days, rats were a pretty common guest in many people's homes - and they loved to chew on everything they could find, including paper. That's why manufacturers began adding margins to notebooks. The idea behind the design was that the rats would first chew the empty margins, leaving the important contents intact.

#3 Brass doorknobs

Image source: Alan Levine Brass actually has antimicrobial properties, meaning they kill a wide range of microbes in a matter of hours.

#4 Pom-poms on beanies

Image source: randomlies Pom-poms may look pretty adorable but they actually served a purpose back in the day - French sailors used to wear them so they wouldn't bang their heads on the ceiling during storms.

#5 Fabric swatches

Image source:  RJ News Most coats nowadays come with a few extra buttons and a little fabric swatch. And while you can use the little piece of material to patch up a hole, its main purpose is to test out cleaning products so you don't accidentally ruin your coat.

#6 Ridges on the sides of coins

Image source: Branko Collin Back when the value of coins was equal to their weight, some people used to try to cheat the system by shaving the edges of coins and using the material to mint new ones. The edges were added as a protection measure, to make it obvious to see if the coins were tampered with.

#7 Rivets

Image source: rohit gowaikar Apart from looking cool, rivets help hold the thick fabric of your jeans together and make them last much longer.

#8 Holes in pen caps

Image source: Trounce As many people love to chew on pen caps, accidental swallowing is not that uncommon. Making a hole in the cap ensures you can breathe even with a pen cap stuck down your throat.

#9 Holes on lollipop sticks

Image source: lily liu The reason for this one is very simple - when molten caramel is poured in the mold, a small bit of it gets inside this tiny hole and ensures that the tasty bit doesn't fall off the stick.

#10 The tiny arrow on the fuel gauge

Image source: Tom Magliery This tiny arrow indicates what all of us forget even years after we've been driving our cars - the side in which the fuel cap is located.

#11 Wrench-shaped screwdriver handles

Image source: thetortureneverstops Some screwdrivers' handles are uniquely shaped so you can slide a wrench over them to create more torque. However, be careful with this one - applying too much torque can easily strip the head of a bolt so use an impact driver when you can.

#12 Double erasers

Image source: kekkoz We've all heard the rumor that the blue part of the eraser erases pen marks yet despite many attempts, it never seemed to work. Well, the true purpose of the different sides of these erasers is a little different. The pink side is used on light grades of paper to delete light pencil marks, while the blue one is used on coarser paper to delete dark marks.

#13 Extra eyelets on shoes

Image source: Kledd The extra eyelets are used when you tighten your shoe around your ankle. That way it provides more stability and keeps your shoe from moving around when climbing or hiking.

#14 Drawer under the oven

Image source: osseous The original purpose of the drawer under your oven was to store food so it doesn't get cold until it's time to serve it. Nowadays we mostly use it to store pans and other kitchen utensils.

#15 Left-hand buttons on women's shirts

Image source: nushtaev_dmitriy The tradition of having the buttons of women's shirts oriented on the left side comes from way back in the day when having them oriented this way was a sign of wealth. Having them on the left meant that a chambermaid dressed you and it was easier for them to button up shirts with this orientation.

#16 Tiny holes in locks

Image source: Hannah Giggles The tiny holes not only help drain water out, but they can also be used to oil the insides of the lock.

#17 Ridges on "F" and "J" keys

Image source: Javier Morales The ridges help users locate the keys on the keyboard by touch, meaning you don't have to look down when typing.

#18 Cedarwood coat hangers

Image source: Curtis Gregory Perry Cedarwood coat hangers not only help retain the shape of clothes better than plastic ones, they also repel bugs and moths, ensuring your woolen coats and jackets remain free of tiny holes.

#19 The "57" marking on a Heinz bottle

Image source: HeinzKetchup_US The number "57" marks the spot where you can tap the bottle to make ketchup come out of the bottle easier.

#20 Tiny holes in airplane windows

Image source: Lenny DiFranza The tiny holes in airplane windows prevent pressure from building up in the cabin and also ensures that the windows don't fog up from the breath of the passengers.