Hello. Had some threads that were kind of 'grindy'. Cleaned off with a touch of WD-40. It seems fine now. Is this a good thread lube? Appreciate the advice, and thanks.
Water Displacement 40 is NOT a lubricant.
It is basically kerosene and is good at removing lubricants.
appreciate that Gerald. The threads on mine are much smoother after putting some WD-40 on them. Question: if you had a light, would you rather have nothing on the threads, or some WD-40. Honest question. Thanks.
I don't know about you but I think my GF would be angry if I use WD40 as lube ;)
It's a wonderful solvent and de-greaser/cleaner but a lubricant, absolutely not. What little lubrication it provides rapidly evaporates. Quick google facts (verified before in bike chain lubricants threads on bikeforums many, many times):
"The product began from a search for a rust preventative solvent and de-greaser to protect missile parts. WD-40 was created in 1953 by three technicians at the San Diego Rocket Chemical Company.
Its name comes from the project that was to find a "water displacement" compound. They were successful with the fortieth formulation, thus WD-40.
The Corvair Company bought it in bulk to protect their Atlas missile parts. The workers were so pleased with the product, they began stealing it to use at home. The executives decided there might be a consumer market for it and put it in aerosol cans.
It is a carefully guarded recipe known only to four people. Only one of them is the "brew master."
About 2.5 million gallons are manufactured each year. It gets its distinctive smell from a fragrance that is added to the brew."
Sorry, sometimes the pedant in me takes over.... H)
I bought some 90% pure silicone plumber's grease at the hardware store .
Works well if used sparingly .
I have been using some lube that I used on my trailer hitch when I had an RV. It is teflon based, and does not harm O rings, but is an excellent lubricant. I put as small amount as I can get on my finger and rub it on the threads. Really smooths them.
Jerry
Where does all this mis-information come from? WD contains no kerosene. It also contains no silicone, or, as popular legend has it, fish oil. It is not a grease and should never be used on bike chains.<edit>well, at lease motorcycle chains, maybe bicycle chains are Ok with it!
It is an excellent light lubricant for things like flashlight threads. I like it because it does not get gooey, sticky, or attract dirt like heavier lubes. Auto mechanics use it frequently on threads to clean and "smooth" out gritty surfaces without leaving a lot of sticky residue behind.
Oh, and it was invented right here in San Diego by the Rocket Chemical Company, in the year I was born, 1953. They changed their name after the success of their best selling product, which has been ranked as one of the two greatest inventions of the 20th Century, along with Duct Tape.
Well, that was kind of the point of the bike chain comment and "lubricant, absolutely not" 
No self respecting cyclist would ever use it as a chain lubricant unless they wanted to ruin one.
Honestly I keep all my threads dry unless they are pain to open. I only grease the o rings if I even bother at all. Nothing wrong using WD40 to clean the black sludge off of your threads but it does little in the way of lube. If that's all you have then better than nothing.
Sometimes thequality of the threads are the culprit. If that's he case some sand paper to smooth out that starting threads will greatly improve the sliding action
Understood, BR, I was responding to the claim it was kerosene and not a lubricant, both claims of which are false. It definitely is not a chain oil or grease.
thanks Troop. I know there is better thread lube out there but this is all I have presently.
By the way, I ride a bike daily. My last bike was a Univega Alpina Ultima. Bought it in 1984 for $700. Stolen in 2005. Rode it for 21 years. Always took it to the do it yourself car wash and degreased it, then blasted away. Sprayed it down with WD-40 afterwards. It was stolen with the original chain! Whatever.
In a pinch, I make up some WD40 type stuff by mixing a little motor oil with some paint thinner. Of course having a can of WD40 is handier and better, I have about 5 cans spread about the basement, garage etc.
Over on knifeforums in the keeping sharp section,where everyone, especially Ken is supersmart, we discussed wd40 for some reason. And we came up with the consensus that wd40 has something in it that evaporates, but it also has a small amount of mineral oil. Which, if you didn't know, it's a pretty good light lubricant and I use it on my carbon steel knives. But when you need something heavy duty, like grease, it won't do. But for something like threads on a light, it's perfect, theres no need for grease. The grease is just messy. I also use wd40 to get rid of greases that have gunked up with particles like dirt. Due to the fact that it's a solvent. Which, once the solvents done working, it evaporates and the mineral oil is left behind.
The long-term active ingredient is a non-volatile, viscous oil which remains on the surface, providing lubrication and protection from moisture. This is diluted with a volatile hydrocarbon to give a low viscosity fluid which can be sprayed and thus penetrate crevices. The volatile hydrocarbon then evaporates, leaving the oil behind. A propellant (originally a low-molecular weight hydrocarbon, now carbon dioxide) provides gas pressure in the can to force the liquid through the spray nozzle, then itself diffuses away.
These properties make the product useful in both home and commercial fields; lubricating and loosening joints and hinges, removing dirt and residue, and extricating stuck screws and bolts are common usages. The product also may be useful in displacing moisture, as this is its original purpose and design intent.
Good response, like what i said, but you truly know what you are talking about :)
hey Sintro, just what you said! I copied and pasted from Wikipedia 
And I'm feeling pretty good about using WD-40 as lube for my threads after this thread. Used it on a Leatherman also...
Good to help! 
Quote
....which has been ranked as one of the two greatest inventions of the 20th Century, along with Duct Tape.
Quote
I love statements like these ...
Ranked by whom ?? friends of Jeff Foxworthy/or Red Greene?
http://www.gallup.com/poll/17881/electricity-retains-power-greatest-invention.aspx
An engineer, a physicist, a mathematician, and a blonde were asked to name the greatest invention of all times.
The engineer chose fire, which gave humanity power over matter.
The physicist chose the wheel, which gave humanity the power over space.
The mathematician chose the alphabet, which gave humanity power over symbols.
The blonde chose the thermos bottle.
"Why a thermos bottle?" the others asked.
"Because the thermos keeps hot liquids hot in winter and cold liquids cold in summer."
"Yes -- so what?"
"Think about it." said the blonde reverently. "That little bottle -- how does it know"?
The engineer chose fire, which gave humanity power over matter.
The physicist chose the wheel, which gave humanity the power over space.
The mathematician chose the alphabet, which gave humanity power over symbols.
The blonde chose the thermos bottle.
"Why a thermos bottle?" the others asked.
"Because the thermos keeps hot liquids hot in winter and cold liquids cold in summer."
"Yes -- so what?"
"Think about it." said the blonde reverently. "That little bottle -- how does it know"?