the mysterious cuts

[NKT]

So how would you normally remove the plug?

[darrel.h]

So how would you normally remove the plug?

You would probably insert the key and pull on the plug.

I think I have a new theory now. I think those cuts are for the ease of lock assembly. I assume you would probably have all the pins in the plug and you would insert the key. Then you would put the first the first spring and driver in and you would slide the plug into it until the driver falls into one of the gaps. Then you turn the key slide it in deeper until you finish. The cuts would prevent the plug from sliding out during assembly.

[NKT]

That would leave the lock jammed solid. The bottom pin can't get into the side of the plug, only the top pin. The top pin stops the plug from moving. The top pin cannot then be reached either with the key or with a pick, and the lock is jammed solid. Not easier at all.

[Shrub]

And turning the plug will not lift the pins back up (which is what i think was meant) as the falt on the slot wont facilitate that.

[NKT]

Indeed.

For once, this leaves me stumped. There is no good reason for them, except to annoy locksmiths.

[Shrub]

Im with you on that one, its not annoying as such as theres ways and mean but the only substainable idea is material saving, a small amount on one lock is nothing but a small amount on 5000 of them is another 700 plugs.

[NKT]

But surely the costs involved in milling the slots would be far higher than any possible saving on a bit of brass? You'd need to make millions of them to recoup the costs of the extra milling machine and operator.

Or are they cast into the plug, rather than cut? They look milled rather than cast.

As regards the marks on the top of the plug, they are heavy filing marks, and it looks like someone wanted to make a "turns one way but not the other" plug. For that to be a factory finish is a good demonstration of how bad that lock must be!

[mh]

Or are they cast into the plug, rather than cut? They look milled rather than cast.

In the pictures of this thread, they really seem to be cut.
There are other locks however, where they are clearly cast.

One explanation for this could be that a manufacturer copied another lock without really knowing what they were doing and why. Could be possible.

mh

[Shrub]

They will be cast and then cleaned up on some locks, it isnt unheard of for the plugs to all be cast in the same factory then shipped out and those that buy them either leave them or clean them up, if the plugs are cheap to buy they may not mind adding an extra few steps to the machineing process, the slots could be cleaned with the same slot drill that will make the holes for the pins (a lock factory must surly machine the holes and not drill them) where labour is rife and material short it doesnt matter if its someone stood at a miller doing them by hand, it still is cheaper, its only my idea anyway.