great material for making picks!

[salzi684]

Dukemurmur, no. It's not going to be measured in a unit of length. The point where a material starts to plastically deform is what you are looking for. It will be measured in some form of Force/Area. It's really not that hard to learn the stuff I was talking about. I would recommend that you get a book on materials and their properties. For now don't worry about all of the complex math just read over some of the chapters and get an idea of the concepts.

[plot]

not sure what the topic is anymore...

anyways, was walking in the parking lot and saw something that looked kind of like a lockpick, a small 2 in 1 type of pick. bent down to look at it, and it was half of a pair of tweezers... for a makeshift pick for a newbie, i suppose if they find some thin tweezers they could grind off the top part on there driveway if they wanted too, then they'd have a somewhat managable small diamond/hookish looking pick.

[i_want_to_pick]

So if Aluminum is better than some steels why haven't I ever seen or heard of manufactured or homemade AL picks? There must be some kind of negative about it to keep them from being made.

Matt

[plot]

Aluminum wouldn't last as long. would bend when picking. etc.

like i said, make a pick out of a popcan and tell us how well it works.

[Chucklz]

NO ALUMINUM WOULD NOT BE BETTER

Proof?

Code: Select all

               Young's Modulus  Ultimate Strength   Yield Strength
              10^9 N/m^2             10^6 N/m^2        10^6 N/m^2
Steel             200                          400                        250
Aluminum      70                            110                        95



This is from Halliday , Resnick, Walker, Fundamentals of Physics, 5E,Extended, Wiley 1997

NB, I am NOT a MechE, or any kind of engineer, just a biologist, but the numbers don't lie.

[Mad Mick]

I've cracked my Aluminum bike frame

I broke my wookie once........

[Mad Mick]

Duke, you really should consider the fact that you are being gently steered by very intelligent/educated professionals here!

[salzi684]

Weather or not a certain steel is stronger than a certain aluminum alloy depends entirely on the two alloys under comparison. Some aluminum alloys would be better suited for making picks than some steel alloys, but this is the exception to the rule.

But what it boils down to is that a decent steel, when considering the optimum qualities in a lock pick material, is better than a great aluminum alloy. But a great aluminum alloy would make a better pick than a bottom of the barrel steel.

Chuck, that chart is only good for one type of steel and one type of aluminum. It is not always the case.

[Mad Mick]

For most of us though Salzi, durability and price is of apparent concern. It's nice to be personally able to obtain exotic materials to make picks out of, but for most of us, these materials are considered to be made from 'unobtainium'.

[i_want_to_pick]

Quote:
I've cracked my Aluminum bike frame

Mad Mick wrote:
I broke my wookie once........

Yea but a new $1200 bike frame shouldn't have cracked.

[Chucklz]

Oh I know that chart is for one steel and aluminum but just as a generalization it tends to steer one to a reasonable conclusion.

[hozer2k]

Let me repeat AGAIN ok:

In ALL cases, steel is going to be about 3 times the stiffness of steel, period!

As far as strength goes, that is a totally different can of worms and we need to consider yield strength, ultimate strength, ductility, perhaps even fatigue life.

In general though steel is going to be a better choice. As someone mentioned, yes it is possible to find a real poor choice steel and and better aluminum (as far as strength, ductility, fatigue go ONLY). But it is far easier the other way around.

So lets recap:

1) Steel is ALWAYS about 3X the stiffness of aluminum.
2) In general steel will have better (overall) strength properties, but not always.

See 1) and 2) for the reason it is not a great idea to use aluminum for a lockpick.

As an aside, the main advantage with aluminum is it is about 1/3 the weight. In many applications this savings will outweigh the drop in stiffness and strength. There are other reasons that aluminum may be advantageous, but that is out of scope for our discussions. Since weight is not a real factor for a pick, aluminum is not a good candidate.

While we are at it...there are many high grade steels out there (that are rather pricey as well) that would make some of the best pics possible.

Examples would be 15-5PH and 17-4PH.

[hozer2k]

Sorry, the first line should read steel is 3 times the stiffness of ALUMINUM in all cases...gosh darn it.

[PYRO1234321]

i was watching this thread for a while, so i figured i would add my 2 cents. regardless of all the numbers and comparisons to objects other than picks (i.e. bike frames) aluminum plain bites for picks of any durability. i've attempted to make picks and wrenches from just about everything under the sun (including some scrap titanium, fiberglass, various plastics, composites etc. etc...). Stainless/carbon/spring steel is the material of choice. Since the invention of locks in general, there have been picks and its no wonder that most are made of these materials.

FYI: titanium (mentioned in other posts) is not very strong in the dimentions of a pick, better than aluminum, but not as good as the forementioned steels (not to mention price). some plastics make good rakes (stiff nylon sheet) for people who use the quick extraction rake method. they can be made with scissors and the slight deformation of the plastic seems to be useful when raking (using standard hook and rake designs of slightly exagerated dimensions). i believe that the slight give may help keep set pins from being 'over picked', however the weakness is no good for pushing stubborn pins (thats what metal hooks are for ).

cheers

[sanskey]

I started reading the posts here a couple days ago and got a lot of good ideas for DIY pics. It seems everyone has their favorite materials but, I didn't see any mention of piano wire.

I had some piano wire on hand ( 3/32" I think. ) and using pliers, file and a small vice I made my second pick. It looks similar to my first pick made from a paper clip but, it's a lot stronger.