My experience with a master lock No3...

[zaphar]

This post is just about an experience I had trying to pick a Master lock No3 that I acquired about a week ago. The lock is old, at least 10 years, and shows many signs of rusting, which is why I even bothered to share this experience. I was working on the lock for a few hours when I first obtained it and had no luck opening it. I could feel the pins setting and the tumbler was shifting but I couldn’t get it to open. I became flustered after working on for a couple of days and decided to search these forums for information regarding Master No3 locks. According to a post, I found, these types of locks were very easy to open, but I was having no suck luck. I was confused as to why it wasn’t opening since it felt like all the pins were set. After some time and repeated tries, I finally figured it out… I was listening to the pins dropping inside the lock by rotating it back and forth. I made out four distinct clinks and assumed that all the pins were set. At this point, I became flustered since all the pins were set but the tumbler wouldn’t rotate anymore than it already had. I decided to try forcing the lock open, which normally wont work; so I took out a screwdriver, popped it into the keyhole and gave it a twist. I didn’t think it actually would have worked but it did, with some force the tumbler began to turn and the lock popped open. I guess I learned a little about picking rusty locks via this lock. If you are having similar problems opening a lock like this one I definitely recommend using a flathead screwdriver on it. After having opened it, I banged it around a little to see if I could get the rust out. I think the internals were slightly rusted since quite a bit of rust dust fell out of it.

[master in training]

tension wrenches are designed to give accurate feedback of what the lock is doing, as well as turning the plug, due to this need for feedback, some of the strength has to be sacrificed, which means they open most locks, but if a lock is stiff or seized, they can bend or snap if too much pressure is put on it, always have a tool such as a flat head screw driver on hand to help turn the plug that last little bit to open it.

[maty68]

I take it you still had the tension wrench in the keyway and applying torque when you inserted the screwdriver, otherwise any set pins would have unset. Also, its the plug that turns, not the tumbler, the tumbler is the pin. Sometimes the bottom pin can be forced past the shear line which when dropped back can give a distinct click that can be mistaken for a set pin click. Having pins go past the shearline can give the illusion that a lock has been picked when all that is happening is the pin is binding against the hull preventing further rotation of the plug.

[Varjeal]

Great job. However, the "tumbler" didn't turn, the plug did. Keep it up.

[Kodack]

If you are feeling the click more than hearing it then the pin is probably set. If it's an audible click, easily heard, then it is probably the pin spring slamming it back past the shear line meaning you pushed it up much to far. Less pressure is better. Pretend your trying to tickle the pins.

[quickpicks]

Sometimes a tension wrench will get caught in the bottom of the lock and the plug will not rotate much. A simple soloution to this for me was to lift up the tension wrench a bt and then try turning the lock. If this does not work, then it is time for the screwdriver.

[quickpicks]

Sorry, I meant rotating the plug.

[zaphar]

Oh, thanks for the correction. Yeah, I've opened the lock several times now and the plug is definitely stiff or something, because I always have to use the screwdriver on it; I can tell I've got the pins set because the key hole looks like this:
|---------|
[ (\) ]
|---------|

this is what the bottom of the lock looks like; the plug is turned more than it could be if any of the pins were not set. When I get to this point, I take out my tension wrench and stick in the screwdirver and give it a twist, it works every time. It just seems strange that it requires so much force to open it, are these locks supposed to be like this?

[rayman452]

I had this with my master lock #3 when I first got it, or something similar. I thought mine had security pins because the plug wouldnt turn, but it turns out that my tension wrench was in too far. I hjave found on these locks, if your tension wrench is in too far, the plug will not turn. Next time, try doing this, but with the tension wrench out more. If you cant do that, then have your tension wrench all the way in, pick it, and when you think you got it, put another one in infront of the pins and remove your previous one, now letting the plug rotate freely.

[raimundo]

A long tensor blade will stop a master plug from turning far enough to open the lock, but it will let the lock turn some so it makes it look like you have the security pin problem. What is in fact happening is that the tensor blade is longer than the key blade, and is reaching through the plug and out the other end, in this position, the lock can be picked, but the plug will jam before turning far enough to open the lock, either pull the tensor blade out while still keeping enough tension on it to keep it from falling back into the locked position, or start over with a shorter tension blade or with the long one inserted not further than the length of the key.

[kodierer]

If I never seen another Master No.3 post my life would be better.

[Kodack]

Oh, thanks for the correction. Yeah, I've opened the lock several times now and the plug is definitely stiff or something, because I always have to use the screwdriver on it; I can tell I've got the pins set because the key hole looks like this:
|---------|
[ (\) ]
|---------|

this is what the bottom of the lock looks like; the plug is turned more than it could be if any of the pins were not set. When I get to this point, I take out my tension wrench and stick in the screwdirver and give it a twist, it works every time. It just seems strange that it requires so much force to open it, are these locks supposed to be like this?

I'm curious what parts of the lock had rusted as it's mostly galvanized steel and brass?

[PickCop]

Not trying to sound sarcastic, but did you try a healthy dose of wd-40 in/on/around the plug?

[PickCop]

Not trying to sound sarcastic, but did you try a healthy dose of wd-40 in/on/around the plug?

Edited to mention a shot of good lube to chase it?