Which material is best for lubricating a door lock?

Graphite is an ideal material for lubricating a door lock because it is a dry lubricant that does not attract dust and dirt. This characteristic is especially important for locks, as a clean lubrication helps maintain the smooth operation of the locking mechanism over time. When graphite is applied to the internal parts of the lock, it reduces friction between moving components, allowing the key to turn smoothly and preventing sticking or jamming.

In contrast, oily lubricants can tend to attract debris, which can build up and cause the lock to become sluggish. Products like WD-40, while popular for various applications, also have cleaning properties and can leave a wet residue that may not be suitable for fine lock mechanisms. Silicone spray can be beneficial for other sealing applications due to its waterproof properties but is not as effective as graphite for the precise needs of a lock's internal mechanisms. Thus, graphite stands out as the best choice for ensuring long-lasting and reliable performance in door locks.