People usually think of WD-40 as as an oil. WD-40 => Water Displacer #40. Is primarily a solvent-based product with just the smallest amount of oil in it.

WD-40 is kerosene
Also don't use this as a rust inhibitor, it may displace water, but it is really actually hygroscopic and will attract moisture to whatever you've sprayed to "protect" and it will quickly rust.

Lightweight machine oils (e.g.3 in one) are considerably lighter than even 5W30, the lightest of the standard automotive oils

tri-flow-vs-wd-40 |

LPS #2

I use the CLP and Triflow less now except to clean and oil hand tools, as I've been using Mobil 1 75W90 for everything except for three items; I still use Lockease on locks, Eezox on my pocket knives, and Eezox and CLP on firearms. The Mobil 1 doesn't seem too thick as it works well on my older (I think I bought it in the 70s) plain bearing Dremel, but I wouldn't use it on locks. It works a LOT better than CLP or Triflow as a lube. I buy WD40 by the gallon as I use it for cleaning and short term protection on most large tools in the garage, including the mower top to bottom, but I don't use it as a lube.

Which-lubricant-to-use | DIY Life
Silicone spray (Triflow, WD-40 silicone) is increasing in popularity as it works well as a sliding lubricant for metal, wood, rubber and plastic. Silicone spray also repels water and is therefore often used to push water out of electrical components.

Synthetic grease has better lubrication properties than petroleum based grease and has a longer life as it resists thermal breakdown and shear.

Marine grease is similar to synthetic grease however it is water resistant and contains a rust inhibiter to prevent metal parts from fusing together due to rust build up. Marine grease is the best choice for items which are continuously submerged in water or exposed to the elements.

Best-spray-lubricant | LA Times
Slick 50 Spray Lubricant - Best Spray Lubricant Overall
3M Silicone Spray Lubricant - Runner Up (dry type)


Penetrating oil
Kroil vs PB-Blaster
A study done by Machinist's Workshop magazine in their April 2007 issue looked at different penetrating oils to see which one did the best job of removing a rusted bolt by measuring the pounds of torque required to loosen the bolt once treated. If the study was scientifically accurate, it turns out a home brew works best! Here's the summary of the test results:
 Penetrating oil ..... Average load
 None ....................516 pounds
WD-40 ................... 238 pounds
PB Blaster .............. 214 pounds
Liquid Wrench ........... 127 pounds
Kano Kroil .............. 106 pounds
ATF-Acetone mix............53 pounds
ATF - Automatic Transmission Fluid
Beyond-wd-40-lubes-for-the-home-shop | HackaDay
In 2012, a group of engineering students from Drexel University studied alternatives to commercial penetrating oils, which are often expensive or hard to come by in developing countries. In a controlled series of experiments, they determined that a simple mixture of vegetable oil and acetone was far superior to WD-40 in reducing the breakout torque of nuts rusted onto bolts. Similar comparisons show that a 50-50 mix of automatic transmission fluid (ATF) and acetone beats the commercial penetrating oils at a fraction of the cost.
ISO GradeEquivalent SAE GradeViscosityDensity
centiStokes10-6 Reyns (lb s/in2)kg/m3lb/in3
40 oC100 oC104 oF 212 oF
32 10W 32 5.4 4 0.6 857 0.0310
46 20 46 6.8 5.7 0.8 861 0.0311
68 20W 68 8.7 8.5 1.1 865 0.0313
100 30 100 11.4 12.6 1.4 869 0.0314
150 40 150 15 19 1.8 872 0.0315
220 50 220 19.4 27.7 2.4 875 0.0316

I could not find any web site which listed SAE grades for common oils tri-flow, WD-40, ...

ISO Grade Oils - Viscosities and Densities. Available at:


PTFE - Polytetrafluoroethylene, which is a synthetic fluoropolymer.
SAE -  Society of Automotive Engineers,

last updated 1 Nov 2022