Scanning Electron Microscope Analysis of Pin Tumblers

[RevDisk]

Fascinating images, thanks to you and the relevant Smarties and Nerds.

I think the coolest thing is the clearly defined spiral where the end of the pins have been turned to a taper. As you say, the different marks are quite easy to tell apart.

No prob. I was just curious what it'd look at at very high resolution. Past 50 microns, I doubt it'd make much of a difference and I didn't want to use other devices to get deeper. I don't need nanometer resolution, as it'd be less informative.

No fair, I don't have (inexpensive) access to such awesome machines

Great shots, though! Something that I've seen with this type of equipment that looks great is a quick impressioning job where there is alot of filing residue along the base of the pin tumblers. Looks neat under the SEM, especially at high magnification.

dg

Appreciate the kind words! I suspect for most folks, your work has much more practical applications. SEM photos are pretty, but not exactly handy in a field environment. Love your site, BTW. Very handy research!

And who said anything about being fair?

I have a few more pretty machines I have not yet employed... Never know, right?

I wonder what a pick gun or electric pick would like like. Hint Hint

Don't have either. Kinda boring, and electric picks tend to play hell on locks. Tho, I have a couple ideas on how to lessen (but probably not eliminate) some of their effects. Someday I'll get bored and do some work with both.

[npdaniels]

lol I wonder what the markings would look like. Always a wise guy on here.

[raimundo]

now take a picture of the rough edge of that pick, and try it again after sanding it,

clearly the pins are rotating so that the straight marks the cross the surface half way or more, appear in different tangent angles.

This kind of 'forensix' would be very useful in proving that a lock with pristine unused pins has been manipulated, but if the key were used every day and carried an occasional grain of sand into the lock...............
the best evidence of picking with a rough pick would actually be seen on the walls of the keyway cutting into the wards where they have edges near the pin holes. to put this under the microscope, the plug has to be sawn in half through the pin chambers, and no slipping any lower into the keyway. any part of the saw cut in the upper part of the keyway may be suspect as evidence, only beneath where the saw cut could you find dependable evidence.

The method would be useless on a lock that has been in use daily by numerous keyholders.

the whole thing needs more study to be able to difinatively say that that is evidence of picking.

brutal marks that can only be made with a rough unsanded pick in the hands of an amateur are found as vertical stria on the sides/not the bottoms of flatbottom top pins, this is true evidence of picking and no other source can be postulated for these marks along the sides of the pins. pickers also leave scratches on the face of the lock that look exactly like the scraches made when the true keyholder picks the wrong key and tries to get it into the lock

perhaps you should look at some of the pins in a practice lock to see obvious evidence of picking, where the pins and keyway as well as the cylinder wall at the bottom of the keyway,

perhaps next time you should show the pointed bottom of a bottom pin. and even try several types, the rounded point, the chamfered point, and the well use pins

Since the pin in the photos appears to be that of a flat ended pin, like a top pin, I wonder if you had your pick inside the shearline break in that collumn.