During a cold snap, when temperatures dropped below freezing, the deadbolt to my garage froze and the key wouldn’t turn. I was renting at the time so I called the property maintenance company who told me to use a hair dryer to unfreeze the lock, so I could get to work. Then the person added “I’ll send someone out to spray it with WD-40.”
Being in the hardware business we hear and learn new things every day. One of the things I learn early on is while WD-40 is good for a lot of uses, it isn’t good to spray in locks.
Our Director of Engineering, Mark McRae, wrote a White Paper on the subject, which we have shared below. There is a lot of good technical information but basically our Director of Engineering recommends using White Lithium Grease for hinges, locks, and other door hardware.
The WD-40 vs White Lithium Grease vs Silicon Spray by Mark McRae
From getting loose a stuck bolt to lubricating metal to metal and metal to non-metal friction areas.
There are a lot of oils/lubricants/greases available for specific purposes and some that will work for a wide range of applications.
Below is information on WD-40, Silicon Spray and White Lithium Grease as they are by far the most popular “multipurpose” lubricant/greases.
WD-40 (Water Displacement, 40th attempt) is a product that everyone uses indiscriminately on a wide range of materials.
* HEALTH CONCERNS: Non-carcinogenic. (From wd40 site)
* DOES NOT CONTAIN: Silicone, kerosene (as many believe), water, wax or graphite. (From wd40 site)
* SHELF-LIFE: Indefinite. (From wd40 site)
* SAFE FOR: Metal, rubber, wood and plastic. (From wd40 site)
* DIELECTRIC: YES (110V short circuit couldn’t be obtained, and multi-meter showed its way above the mega-ohm range, probably in giga-ohms)
* OUTDOOR’: YES (But needs to be reapplied regularly)
* USES: Removes sap, tar, adhesives, labels and tape from surfaces without damaging existing paint*. It’s an effective cleaner for tools, equipment, and vehicles. Use it to remove splattered bugs from the front of cars. Remove gum from carpet. (From wd40 site).
WD-40 DISPLACES WATER, PENETRATES, PREVENTS CORROSION AND CLEANS. (From wd40 site)
* NOTES: A lot of people suggest and report that it will eat some plastics and rubber. Most agree that it won’t protect for long if exposed to weather conditions. Many say it will damage paint and the rest that it will work for light duties like home improving jobs.
* RECOMENDATION: Use primarily to loosen tools, bolts, indoor residential door hinges, and things that don’t need any special care (things that can’t be easily damaged). Also I must say that once the product dries, the residue won’t protect as much as when recently applied. It does prevent corrosion but won’t work very well if used outdoors. Never use it for high friction surfaces and definitely never stain porous painted surfaces with it, as it’s harder to remove, and may remove the paint. Do not spray it into a used lock cylinder as it will collect all of the residual dust and metal grit in the cylinder and possibly turn it into a paste. For locks, use either a dry graphite powder or a graphited lock fluid such as Lock-Ease ®.
My personal recommendation is to use it only on tools, bolts, electric contacts (for example the screw in light bulbs and audio jacks), and things that aren’t likely to be damaged by chemicals. I regularly spray some inside the electrical outlets with help of the straw.
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WHITE LITHIUM GREASE
White lithium grease is a product used for some in heavy/middle-duty applications.
Please note that properties from different products may vary.
* HEALTH CONCERNS: Non-carcinogenic (Suspected). Mist or vapor can irritate the throat and lungs. High concentrations may cause nasal
and respiratory irritation and central nervous system effects such as headache, dizziness and nausea. Intentional abuse may be harmful or fatal.
Skin Contact: May cause mild skin irritation with short-term exposure with redness, itching and burning of the skin. Prolonged and/or repeated contact may produce defatting and possible dermatitis.
Eye Contact: Contact may be mildly irritating to eyes. May cause redness, stinging, swelling and tearing.
Ingestion: This product has low oral toxicity. If swallowed, this material may cause irritation of the mouth, throat and esophagus. This product is an aspiration hazard. If swallowed, can enter the lungs and may cause chemical pneumonitis, severe lung damage and death.
Chronic Effects: Prolonged or repeated skin contact may defeat the skin resulting in irritation and dermatitis.
Medical Conditions Aggravated by Exposure: Preexisting eye, skin and respiratory conditions may be aggravated by exposure (From 3-in-one site)
* CONTAINS: Petroleum solvent, lithium grease, zinc oxide, propane, n-butane. (From 3-in-one site)
* SHELF-LIFE: Indefinite. (From another product can label)
* FLAMMABLE: YES (Combustible liquid and vapor from 3-in-one site) when tested for flammability (once applied and using different brand), the grease will catch fire; however, it would extinguish itself almost immediately. Some brands may contain fire retardant chemicals. Look for this if your application dictates.
* SAFE FOR: Metal (From what I’ve researched). As a petroleum distillate, wouldn’t use it for plastics or rubber; it will probably damage them in the long term.
* DIELECTRIC?: Not stated in specifications, but tested by short-circuiting 110V with the grease and nothing happened (grease placed on a flat surface, and on both sides of the applied product, put the cables so that the grease would cause a short circuit) The multi-meter showed it’s above the mega-ohm range, probably giga-ohms.
* OUTDOOR?: YES, long lasting, withstands high temperatures, water and won’t freeze. (From 3-in-one site and DuPont White Lithium Grease product site)
* USES: Hinges, locks, latches, seat tracks, strike plates, cables, distributor cams, battery terminals, radio antennas, windshield wiper mechanisms, bolts, bearings, sliding doors, windows, appliances, lawn and garden equipment, garage door tracks, chains, screws, guns, tools, machinery, fans, blowers, roller channels, chains, conveyor, bearing, gears, pneumatic tools, blades and bits.
* NOTES: From research, and according to the uses specified by the 3-in-one site, white lithium grease is commonly used for metal to metal friction surfaces and metal moving parts.
* RECOMMENDATION: Use it only on metal, especially for moving parts and friction areas. I don’t know what surfaces it may damage, (paint, wood, etc.) but if something gets stained, clean it right away.
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Silicon spray is a product used mostly like a replacement for WD-40, because it is known to be safe for plastic, rubber, wood, metal and other surfaces.
Please note that properties from different products may vary.
* HEALTH CONCERNS: CARCINOGENIC VERY HARMFUL
Eye Contact: Irritant. Prolonged contact may cause conjunctivitis.
Skin Contact: Irritant. Defatting of tissue, dermatitis may occur.
Inhalation: Irritant to mucous membranes. Repeated exposure may cause narcosis..
Ingestion: HARMFUL OR FATAL IF SWALLOWED. (From Liquid Wrench site)
* CONTAINS: Aliphatic Hydrocarbon Solvent
Low Odor Base Solvent
Naphthenic Petroleum Distillate
Xylene (mixed isomers)
(From Liquid Wrench site)
* SHELF-LIFE: 18 months after shipment date (From another product can label)
* FLAMMABLE: YES (From Liquid Wrench site) Didn’t test flammability because of health concerns.
* SAFE FOR: Rubber, wood, plastic, metal and painted areas (From Liquid Wrench site and what I’ve researched)
* DIELECTRIC: YES (from Liquid Wrench can label and TESTED)
* OUTDOOR?: Haven’t tested, but wouldn’t expect it to last more than WD-40, as consistency shows it’s very thin.
* USES: The same uses as WD-40 EXCEPT where there is a risk of fire, as it is very flammable (both propellant and liquid). And also it can be applied to materials listed as safe, so I believe this is a more versatile product. Some people I’ve heard trust this product so much that they have used it in safety critical applications such as car ignition system and brake caliper boots.
* NOTES: This is a very toxic product, some people say it has a pleasant odor, but inhaling its fumes is not something I would do. I don’t know if the toxicity refers to the vapors when it’s being applied or to the product itself). Use it with responsibility.
* RECOMMENDATION: Would use it in those places you would want to use WD-40 but aren’t sure about damage to surrounding materials, and to lubricate and to some extent, protect those materials as well. For example some precision mechanisms, slide windows and to get loose and/or prevent rust in stuff with different materials (plastic and metal, metal and wood, etc.) The can also states it’s safe for vinyl.