WD-40 was first used by the military in the '50s to clean up Atlas missile parts. Today, it's used by people everywhere to clean up virtually everything in need of a gleam. But don't go spraying the stuff just anywhere. WD-40 can cause more harm than good to certain household items. The DIY enthusiasts at Stack Exchange chime in.


Photo by Jorge Barrios.

It seems like WD-40 can be used to lubricate just about any moving metal part. But is this true? Are there instances when WD-40 can be harmful?


— sharptooth (originally asked here)

Answer: Hold Up...

WD-40 isn't actually a true lubricant. WD stands for "water displacing" and its main use is as a solvent or rust dissolver.

G/O Media may get a commission LG 75-Inch 8K TV Buy for $2150 from BuyDig Use the promo code ASL250

The lubricant-like properties of WD-40 come not from the substance itself, but from dissolving components. And the effect doesn't last.

WD-40 can be a good substance to start with — it can help clean up rust or other grime. But depending on what you're working with, you should probably follow up WD-40 with use of a true lubricant such as one based on silicone, grease, Teflon, or graphite.


— Answered by Cody C

Accepted Answer: Firearms, Drive Chains & Gears


Firearms - You should never use WD-40 to clean or maintain firearms. WD-40 is hygroscopic and will attract moisture to the firearm which will result in rust.




Drive chains of any type - Because WD-40 isn't a lubricant, it really will not work well on drive chains of any type.




Gears of any type - WD-40 doesn't have enough lubrication affect to be useful on any type of gearing. Only specified gear lubricants should be used in this case.

— Answered by nevadaexile



Answer: Door Hinges


Never JUST use WD-40 on door hinges or anything you want to keep clean. It attracts dirt and dust. It will turn your hinge pins black.

— Answered by shirlock homes



Answer: Bicycle Chains


WD-40 can wash dirt into a bike chain, ruining the chain and taking out the gears along with it. Stay away, cyclists.

— Answered by Mathew



Answer: Musical Instruments


My sister works at a music store. She said a dad ruined his kid's $800 clarinet by using WD-40 on "the squeaky part" — and no, that isn't the entire clarinet.

— Answered by AnonJr



Alternative Answer: Rubik's cubes


Serious cubers will lube their cubes with Jigaloo, CRC silicone, or even vaseline. They will point and laugh at noobs who use WD-40, which contains petroleum distillates (paint thinner) that can melt and seize a cube. Crazy, I know, but noobs keep doing it.

— Answered by cidermonkey







Think you know where WD-40 should never go? Leave your suggestion in the comments or submit it at Stack Exchange, an expert knowledge exchange on diverse topics from software programming to cycling to scientific skepticism.

