What works best actually depends on your environment. This article explores lubrication technologies, how and why they work, and what to look for. Plus, we’ll give you some popular internet lube test links.
Need to know:
- Your environment matters.
- Cleaning out previous lubricants avoids compatibility problems.
- Cost, convenience, and customer satisfaction will drive your choices.
Clean Keyway
A typical rookie mistake is to shoot something into a keyway and wind up with sludge. Dry lubricants like graphite or powdered products were commonly used in factory-installed pin-tumbler cores or cylinders for many years. Adding “wet” lubricants will turn these dry materials into mud. Mixing unknown lubricants can lead to unintended consequences.
Cleaning the cylinder or core well before field lubrication avoids these problems. The same goes for lock and exit device chasses. Although the original WD-40 is seldom used on locks today, it can be used as a temporary penetrating oil measure for sticky cores or locks, but it is not a lubricant. Acetone is an effective solvent for really serious cases, but it can damage painted finishes and the fumes are dangerous.
The same goes for lock and exit device chassis. A number of industry professionals suggest the best cleaning results come from using a contact cleaner, or an acetone or other solvent-based cleaner like CRC’s tetrachloroethylene. Home Depot, Lowes, Ace Hardware, and Amazon all have solvent and contact cleaners priced from $10 to $18.
Caution: Contact cleaners and solvents may have high VOC (Volatile Organic Compound) ratings. Do not light a cigar after spraying in a closed room, unless you want to spend a month in a burn center. As I write this, I’m still taking a few deep breaths after using just a few drops of acetone in a closed room.
Wear safety glasses. You do not want a single droplet of hazardous chemical mist in your eye. The good news is that aerosol contact cleaners and solvents are cheap and flush dirt, oils, graphite, and grease out of lock cores and cylinders. The volatile alcohol or other carrier evaporates rapidly, leaving clean metal ready for lubrication.
Be aware that some degreasing products also require rinsing. This is likely counterproductive to installed keyway lubrication.
Clean and Lube
Several products are effective at cleaning keyways, as well as leaving a well-lubricated metal surface. These may be carried in alcohol or with cleaning solvents and light synthetics that lubricate. Examples include Poxylube CP-200, Houdini, and some others. Poxylube cleans with a solvent base, leaving a slick PTFE coating. Houdini uses cleaning solvents and deposits low viscosity synthetic lubricants. We also found that some PTFE products in an alcohol or solvent base performed well by cleaning and leaving a very slick surface.
Cleaning and lubricating with a single product does speed the field service process, but we have not done long-term tests to reach any verifiable conclusion as to relative lubrication intervals.
Locksmith Jason Meeks of SE Lock & Key in Jackson, MS has produced two rather extensive video tests, exploring corrosion protection and lubricity. “Lube Off 2” on YouTube (below) is an informative hour-long test of 19 -different lube products.
The science
Keyway lubrication products might include PTFE (Teflon), silicone, graphite, synthetic petroleum, and lanolin. Here we’ll explain how each of these chemicals works in various environments. Later, we’ll cover what we know about lock and exit devices. This should help you understand what works and why.
PTFE (Teflon) is short for polytetrafluoroethylene, a dry chemical that is one of the slickest substances known to man with a .04 coefficient of friction. The material adheres well to metal surfaces, provides decent lifecycle for precision keyways, has extremely low moisture absorption, wide temperature range, resists chemical attack, does not attract dust, and provides moderate corrosion protection. Service life doesn’t appear to be as long as synthetic petroleum or graphite.
You will find PTFE in a large number of aerosol spray products and powdered form in popular lock or hardware outlets at modest cost. PTFE is now frequently combined with solvents or other compounds or mixtures like in the Tri-Flo PTFE product that perform multiple roles.
Graphite is a much-maligned lubricant that was used by lock manufacturers for many years. The major benefits are extremely long service life in keyways, low cost, ease of application, and it is really slick. I once observed factory staff lubricating precision keyways with graphite. They dipped a key in a graphite tray, then tapped the key to shake off excess product. The key operated the plug four or five times, was wiped off, and packaged. There was not enough excess graphite to show up on white clothes.
Graphite adheres well to metal surfaces, lasts much longer than other products, and does not attract dust. There are two downsides. The first is that way too much graphite is frequently applied, creating dirty keys, and an over-lubed environment. The second is that graphite’s high porosity allows moisture absorption. Graphite can cake in the keyway if moisture or other lubricants are introduced. Graphite is not popular in moist or coastal regions, but gives extremely long service life in interior locks or dry conditions when used sparingly - very sparingly. One puff from a squeeze applicator is plenty.
Spraying other lubricants into a core containing graphite was one of my own worst rooky mistakes. It’s prudent to flush existing graphite (or anything else) out with aerosol contact cleaner or solvents prior to introducing other lubricants. Houdini, Poxylube, and some aerosol PTFE products performed well cleaning and lubricating in a single application.
Silicone is another popular lubricant. Whereas PTFE (Teflon) is thin and hard, a silicone layer is thicker, moist, and more flexible. This lubricant repels water and protects well against rust. Silicone works best in moist conditions, but we’ve not seen it used often in dry or dusty atmospheres.
Lanolyn is a natural lubricant harvested from sheep’s wool. The substance is known for its exceptional rust preventative properties and adherence to metal surfaces. Low-viscosity formulas can even penetrate into microscopic fissures where electrochemical corrosion can begin.
Medeco has recommended a lanolin-based aerosol product called Fluid Film. The product remains moist, and is reported to hold up well in high-traffic applications. Since the Fluid Film product does not contain any solvents, they recommend first cleaning the keyway with contact cleaner before lubricating. Temperature range is from 32 degrees F to 120 degrees F, so it is not appropriate for outdoor environments where temperatures dip below freezing. Product literature recommends annual cleaning and re-lubrication, or more frequently in hot, cold or dusty conditions.
Synthetic Petroleum products were developed to handle extreme temperature conditions of high-performance military engines prior to World War II. By the early 2000s, synthetic petroleum oils were the standard for most internal-combustion engines, and have found their way into many other mechanical applications as well. The benefits from using synthetic oils in precision cores or cylinders include excellent lubrication, rust protection, and long operating life.
LPS-1 is a classic synthetic petroleum, although a number of other products now use synthetic petroleum as well. Our own experience (confirmed by several others) was that cores or cylinders should first be cleaned thoroughly with a contact cleaner or solvent. The synthetic petroleum is then sprayed into the keyway, and the key operated several times to coat the pin segments. The cylinder or core does feel very slightly oily for a brief time, but we found it provided excellent service life in the Southwest desert – even after a huge haboob dust storm.
Although Houdini is very protective of its actual product contents, they state that the formula does not contain grease, graphite, PTFE, or silicone. The lubricant does, however, contain low-viscosity synthetic base oils and solvents. The product has become rather popular in the locksmithing community as it cleans and lubricates in a single pass.
After cleaning and lubricating, I found no discernible difference in operation between PTFE, Graphite, Houdini, 3-in-1 Lock Lube, or LPS-1 in precision cores.
Lock and Exit Device Chassis
I recently surveyed several fire exit stairwells where it appeared there had been no lubrication or service for possibly 20 years. In that case, 35 percent of the doors did not latch. Clearly, lubrication was an issue.
Higher viscosity grease lubricants are important in lock and exit device chassis, whereas precision pin tumblers require a slick surface, and very low resistance. My research for this article found service information available from Best, Detex, Precision, Schlage, Sargent, and VonDuprin. All recommended annual lubrication.
Manufacturers also advised flushing with contact cleaner or a solvent like acetone for more serious dried-out grease.
Lock manufacturers generally prefer synthetic grease. Allegion’s Schlage and VonDuprin as well as dormakaba’s Best and Precision use Duralube grease on lock and exit device chassis. Detex uses Syn-Tech’s NS-10895-G grease, a PAO synthetic. Unfortunately, these products only come in bulk industrial quantities. Von Duprin does offer the Duralube product in a 4-oz squeeze tube for about $15 – enough material to lubricate a few exit devices. There are other options.
Several manufacturers advised that timely exit device lubrication (with grease) is far more important than the actual brand. All cautioned against applying excessive grease. Some observed that white lithium grease eventually presents a firmer surface, while other grease products may remain pliable longer. Watch out for costly highly-specialized lubricants. Some intended for medical or food processing applications are extremely expensive.
Super Lube and others are inexpensive medium viscosity products found on Amazon or in auto parts stores that should work just fine for lock and exit device lubrication. Although annual lubrication is recommended, my experience has been that owners seldom have any lock or exit device maintenance program. Bottom line; do what you can.
In some cases you’ll find galvanic corrosion occurs when two dissimilar metals are subjected to a corrosive atmosphere (like salt spray). The Formula 8000 Industrial Lock Lubricant is reported effective on padlocks in salt spray and acidic environments. The Lube Off 2 video on YouTube covers a number of other tested products.
Locksmith Ledger contributor Wayne Winton also put the lock lubricants to the test in the video below. "There's a whole lot of disagreement and confusion out there about what is really good for your locks," he said, adding that a lot of them have the same ingredients and are just branded differently.
Conclusions
Your customer’s operating environment matters. Temperature-controlled indoor applications are no problem for dry or powdered products like graphite. Products that stay moist won’t work as well in dusty areas. Wet or corrosive environments appear to do best with synthetic oils that dry well while protecting against corrosion. Although many synthetics work to 40-below-zero (F or C), there are some cases that require even lower temperature ratings. The January 2024 Locksmith Ledger features an article on Lock Saver synthetic lubricant used in Alaska.
Cleaning out existing (especially unknown) lubricants saves expensive callbacks. Aerosol cans of contact cleaner tend to work well in keyways, with Acetone and other solvents that leave clean metal being effective in lock or exit device chassis. Poxylube, Houdini, and some others do a fine job of flushing existing materials from keyways while leaving a lubricant in one pass.
One caution: Penetrating oil is not a lubricant. Even the original WD-40 makes things work great for a few days - very few.
Several years back, a highly respected lock manufacturer actually did some internal life-cycle testing (as related to me by one of their mechanical engineers). The test apparatus ran a key in and out of a test core, for 100,000 cycles with graphite, 50,000 cycles with LPS-1 (synthetic oil), and 25,000 cycles with Poxylube CP-200 (PTFE). I’m advised that this manufacturer currently uses the LPS-1 synthetic oil in all cores and cylinders leaving the factory. Bottom line; use what works in your environment.
Cameron Sharpe, CPP, worked 30 years in the commercial lock and PACS industry. Contact him at [email protected]
