Understanding Friction and Lubrication on Door Hinges

Friction is a force that opposes motion between two surfaces in contact. When you open or close a door, there is friction between the moving parts of the door hinges.

Door hinges consist of metal parts that rub against each other. This rubbing causes friction, which can make the door hard to open or close and can also cause squeaking sounds. This friction also leads to wear and tear on the hinge components over time.

How Oil Affects Friction

Oil is a common lubricant. Lubricants are substances applied between moving surfaces to reduce friction. When oil is applied to door hinges, it forms a thin layer between the metal parts that are rubbing.

Instead of the metal surfaces directly contacting and creating high friction, the surfaces now slide over the layer of oil. This sliding motion within the oil layer has much less resistance compared to the metal-on-metal rubbing.

Therefore, applying oil to door hinges introduces a layer of lubricant that separates the moving parts, significantly reducing the force opposing their motion.

Conclusion on Friction Change

Based on how lubricants like oil work, applying oil on door hinges will reduce the friction between the moving parts. This makes the door swing more smoothly and quietly.

So, if we apply oil on door hinges, the friction will:

• Increase: Incorrect, lubricants reduce friction.
• Decrease: Correct, oil acts as a lubricant reducing friction.
• Disappear all together: Incorrect, while significantly reduced, some minimal friction will still exist.
• Remain unchanged: Incorrect, applying a lubricant has a significant effect on friction.

Thus, applying oil on door hinges leads to a decrease in friction.