Lets have a serious talk about WD-40 as a skate bearing lubricant. If you don’t have time to get serious, the TL:DR is that we do not recommend using the WD-40 Multi-Use Product in your skate bearings unless you are in a pinch and it’s your only hope.
First let’s start with what the WD-40 brand name is said to mean. From the history of the WD-40 company they say it was a Water Displacement product perfected on the 40th try. The original WD-40 Multi-Use Product was then used by aerospace contractor Convair to protect the outer skin of the Atlas Missile from rust and corrosion. Clearly the chemical mixture has its credentials in protection of metals like those found in our skate bearings.
Many people will tell you the WD-40 Multi Use product is great for lubricating all kinds of things. In the past I have seen lists of the top uses for it that included lubricating skate bearings, but the manufacturer themselves does not include that as one of their 2000 plus uses. They do list skate related uses such as:
- Removes gunk from rollerblade bearings
- Removes gum from skateboard axles
- Helps break in shoe portion on new roller skates
- Protects trucks on skateboards (from what I don’t know)
There are also some non-skate bearing lubrication uses listed, but the WD-40 company themselves don’t point to using it in other similar bearing applications such as bicycles.
The WD-40 Multi Use Product does include, in its formulation, oil that itself could be a good bearing lubricant. But we need to look at the typical contents of the formulation. The Material Safety Data Sheet (MSDS) for the product gives us some guidance on what is in the blue and yellow spray can. It seems to vary by region, but it is generally something like:
- ~60-75% aliphatic hydrocarbons or Naphtha
- ~25-35% petroleum base oils
- the remainder is the propellant such as Carbon Dioxide in the pressurized spray can version
The aliphatic hydrocarbons/Naphtha are essentially thinners for the oil. This is the reason it’s not an ideal lubricant as they will affect the viscosity and lubricity of the base oils. That’s great for some applications but not for the use case of skate bearings. The WD-40 Multi Use Product will provide some lubrication and protection for your bearings but ultimately will be short lived and insufficient. If you do use as your only hope it we recommend that you clean and lubricate your bearing with something more suitable as soon as possible.
There are alternatives at the local department store or hardware store (and sometimes even grocery store). The WD-40 Company themselves make 3-in-One Multi Purpose Oil. It does have a very small amount of Naphtha in which with thin it a little, but it’s still an OK choice. Another common hardware store lubricant is Super Lube Multi-Use Synthetic Oil (with PTFE). Whether or not either of those as as good at more expensive oils emblazoned with skate company logos is a topic for another day, along with testing of other hardware store lubricants.