Mass of pins

[Lelandwelds]

Has anyone tried playing with pin weights and spring tensions? For example, light weight aluminum or magnesium pins mated with a stronger spring? Or, tungten pins used with a lighter spring?

[GWiens2001]

The aluminum pins would wear very quickly. Have not played with pin weights, but spring tension is a common way of trying to address bumping threats.

Gordon

[gumptrick]

I haven't done any of this personally, but it does seem like something that could affect bump resistance. Some locks do have hardened steel pins as opposed to the more common brass. The purpose of the hardened steel is to better resist a drill attack on the core.

I have seen some locks that have an "Anti bump pin", but I'm not exactly sure how those work. I will hopefully have a lock like that in my possession this coming Monday. If it shows up as expected I'll gut it and take a look as to what's in there exactly.

Another method that has been used to deter bumping is the so-called "Murphy Ball". The idea of that mod is to remove one of the pins and replace it with a very strong spring and a ball bearing. The ball bearing fits against the plug hole, holding it place like a ball detent. This makes the lock difficult to bump because bumping requires light tension, but the ball detent requires you turn the key quite hard to overcome it.

[Lelandwelds]

Murphy ball ! That's a slick idea. Tricky. So, it replaces a pin? It's not something extra like a slider?

2024 aluminum wears well. How about titanium or one of the engineering plastics?

[Lelandwelds]

How about one of those high % fiber filled plastics? They're so scratchy it might work like micro serrations.

I cant even pick a lock yet so its dumb for me to "what if". But, I've been thinking so much about grinders and drills my mind is racing in all directions at once.

[Jacob Morgan]

The Ilco Bump-Halt kit includes low-mass top pins and stronger springs. Seems to work well when one or two are added to a lock. I don't much care for bumping, but the kit was given a thumbs up by Deviant Olam in one of his books. The pin is brass but the spring goes around most of it and it weighs less. Last time I bought a kit (from CLK?) I think it was under $10 for enough parts for 5-10 locks.

Regarding a detent to mess with tension, I made one of those a couple of years ago. Have not tried bumping it, but I could not pick it. Not that I am anywhere close to the world's best picker, but fair to say it does make picking harder. I drilled and tapped the empty #6 chamber of a shell and found a bolt that would fit it (a set screw would be best). The hole in the shell has to be made larger in diameter and allow the ball to sit in it. Then put in a detent ball and spring. That is all there is to it. The detent and spring came from Brownells--gunsmiths use them on revolver cranes to improve cylinder lockup. Kwikset filed a patent on the idea a few years ago, so I would not sell such locks unless you want a fight. I think there is enough prior art that their patent would not hold, but it could be expensive in the mean time. I would worry about the detent wearing down the pin hole on the brass plug over time and losing some effectiveness. Kwikset sat on the patent, mainly they did not want anyone else doing it. Apparently the "Smart" lock they have is their response to pick resistance.

[gumptrick]

Murphy ball ! That's a slick idea. Tricky. So, it replaces a pin? It's not something extra like a slider?

All the ones I have were something of an amateur job. I don't know if anyone is producing that design professional. Of course the amateur modification does remove one of your pins, but if someone made a professional design it could be located elsewhere on the cylinder and thus wouldn't cost you a pin.

2024 aluminum wears well. How about titanium or one of the engineering plastics?

Yes, 2024 has great wear characteristics. But it has poor corrosion resistance. That could be a concern, especially with dissimilar metals in contact with each other. Titanium would work very well. It's about half the density of steel and has excellent corrosion resistance. I have done a lot of work with the fancy engineering plastics over the years. I actually used to manage a polymer research lab at a major US university and specialized in doing wear testing on those kinds of materials. I think they would be plenty durable to work as keypins. I can see two concerns though:
first, they could make the lock suspectible to a thermal attack: i.e. heat the core up with a torch and then when the plastic is soft just twist the core with a screwdriver
and second, many of those engineering plastics like Ultem contain a large percentage of glass fiber as a reinforcing agent. That stuff is highly abrasive. Our test equipment in the lab would use a polished tungsten carbide ball to press against the plastics and you could easily see the balls wear out over repeated motion. If you had a normal brass key being inserted into a lock whose pins were made of a plastic containing abrasive fillers I could see it wearing out the key rather quickly.

[Lelandwelds]

Is corrosion in locks much of a problem? Titanium causes corrosion problems too. (Except when it is paired with carbon fiber.)

I was thinking UHMW and relatives. I didnt consider heat attacks. I guess you have to worry about fluoric and nitric also. My background is sales of welding and industrial supplies and 3M adhesives. Other than pc boards, firearms, and electric components, i haven't seen much fiber filled plastics. Ultem is a weird one. I ve only seen it used on 3d printer beds. Oh, and one custom knife handle.

What is the design life of a lock? A key? How many insert/remove cycles? It sounds like you're thinking in the 10k or 100k range. My house may be atypical with about 6k in a ten year period.

[greengrowlocks]

I thought it would be fun to make pins for a challenge lock out of these grade 5 titanium rods. I originally bought them to make a tension wrench but they were too small. They still might be too thin for pins as they measure 2.55mm. I don't think they would function any different then brass ones but it would interesting.

[gumptrick]

Is corrosion in locks much of a problem? Titanium causes corrosion problems too. (Except when it is paired with carbon fiber.)

I'm not a professonal lock designer so I couldn't say with certainty, but I imagine it is a major concern. A lock has to be reliable, and having various dissimilar metals in contact with each other is a recipe for galvanic corrosion. Not a good thing to have in a mechanism involving many small moving parts and precision tolerances. I suspect that's why brass is such a common material for use in locks--it has excellent corrosion resistance. And of course you have special marine models that are meant to handle saltwater exposure.

Titanium has excellent corrosion resistance. In fact that's one of the major reasons why it gets used for industrial applications--it not only has fantastic corrosion resistance, but especially at elevated temperatures. Though titanium is infamous for galling in tight fits, especially involving dissimilar metals.

I was thinking UHMW and relatives. I didnt consider heat attacks. I guess you have to worry about fluoric and nitric also.

UHMW has excellent wear resistance so I see no reason why it couldn't be used for pins. (heat attacks aside)
I wouldn't worry about the acid. I've never heard of anyone acid attacking a lock, and it seems impractical because unlike in the movies acid doesn't magically dissolve metal instantly with a simple splash. If you immersed a lock into a container containing a lot of strong acid it might eventually dissolve, but you're talking hours if not days. That's not really practical to use against a lock that's hanging on a hasp or chain. And hydroflouric acid specifically? That stuff is amazingly dangerous. Not so much to the lock but to the crook. If a criminal were to splash some on himself then that would be game over. It doesn't cause much surface damage (chemical burns) but it does get into the bloodstream and destroys your blood cells & bone marrow. Extremely nasty stuff. A crook carrying that around would be like carrying a loaded gun pointed at his own head.

What is the design life of a lock? A key? How many insert/remove cycles? It sounds like you're thinking in the 10k or 100k range. My house may be atypical with about 6k in a ten year period.

The only data point I have there is from last week. I was browsing around reading manufacturer's info on cores and I came across one that said their cores were tested for 40,000 key insertion-removal cycles. Alas I don't remember what company or model core that was so I have no idea if that was on the "low end" or "high end" models. Of course durability/lifetime would be totally different between a budget residential lock vs. something that was meant to be used on a busy commercial or industrial application.

[kwoswalt99-]

The only data point I have there is from last week. I was browsing around reading manufacturer's info on cores and I came across one that said their cores were tested for 40,000 key insertion-removal cycles. Alas I don't remember what company or model core that was so I have no idea if that was on the "low end" or "high end" models. Of course durability/lifetime would be totally different between a budget residential lock vs. something that was meant to be used on a busy commercial or industrial application.

ul437 requires at least 10k cycles without failure, so you can look up wether or not a lock has that rating.

[Lelandwelds]

My understanding is titanium makes steel and metals lower on the corrosion scale work like zinc on steel. Remington had some corrosion problems on one of their auto shotguns. Their solution was to separate it with carbon fiber. I have only been around 6AL4V and CP. I dont like it because it is a PITA to weld. I REALLY don't want to start a flame on something I have only passing familiarity with.

I really appreciate you guys sharing your experience. I've learned to not spend the money until I know the terrain and have a workable goal in sight. This lock picking is like learning a foreign language. Its easier if a native speaker is available. Now I need to google Bump Halt kit and Deviant Olam .

I don't know where I am heading with this new hobby or problem. I feel like "my" solution will include hidden locks, tougher than its obvious appearance, and armored hasps. I think " too much time and trouble" to steal will be my method.

[gumptrick]

My understanding is titanium makes steel and metals lower on the corrosion scale work like zinc on steel.

Yeah, that's galvanic corrosion, rather than corrosion in general. That's what I was referring to when I mentioned "dissimilar metals" in my above posts. Basically any time you have two different metals in contact with each other and there is something electrically conductive present (like moisture), a very weak battery is formed. It literally generates a tiny amount of electricity, and that is responsible for causing corrosion. You can read more about it here:

https://en.wikipedia.org/wiki/Galvanic_series

...basically, the further apart on that list the two metals in contact are then the worse the corrosion will be. However, the metal near the top of the list will not corrode, whereas the one near the bottom will. Note that titanium is very high on the list. Thus most of the time It's not the titanium itself that's corroding, it's whatever it may be touching. It sounds like Remington fixed the problem on their shotgun by adding an electrical insulator between the Titanium and whatever it was touching.

I feel like "my" solution will include hidden locks, tougher than its obvious appearance, and armored hasps. I think " too much time and trouble" to steal will be my method.

I would agree completely.