Best material for picks ?

[Jacob Morgan]

Yield strength has to do with deflection, at what point would something bend.

Reviewed an old text book when I got home, yield strength would be where metal would begin plastic deformation but before breaking, as in tensile strength. I think that would relate to deflection, but I think it would not be that relevant to picks.

Properties of metals are: tensile strength, elasticity, yield, ductility, brittleness, toughness, and hardness. Some of those are not easy to quantity or measure directly and, again, really depends on heat treatment. For a pick it should not be brittle and should not be very elastic.

[WestCoastPicks]

I think if you want to take an educated look at this question, you have to define "Best".
Is Best longest lasting? (Best Quality), or is it longest lasting for the Best price? (Best value).

I think it is the best price for the longest lasting material. All other things being equal (Width and thickness).
For me, that is wiper inserts. I can go to my local auto wrecker and pay him $1 per used wiper (has 2 inserts 24" long if you take the right one).
And has even let me have a wack for free a few times. Also have to replace the wipers on all 3 of my own vehicles every year or two. Ask my friends to save them etc... Most the time they are free.

I am quite light on tension, but even though, these are tools we use and are going to wear out regardless of what it's made out of.
My wiper inserts last quite a long time, about as long as a sparrows with regular use. Even longer if you're talking about sparrows noodle, err sorry I meant short hook. They don't last as long as a Peterson, but with 15 minutes of work, I have Whatever pick I want, that will last for quite a long time, not break off in a lock, and outlast some commercial branded picks, for like $0.10.

But that's just me. Thinking about it all logically and stuff.

[Drifty Flintlock]

So I did check out 1095 steel. One thing that stood out to me is that it seems to have a higher yield strength than many forms of stainless. That surprised me. I thought stainless would probably be stronger in general. Or is it just that spring bends back more easily rather than breaking? Seems like the only picks that talk about the metal they use are 301 stainless (Sparrows and SouthOrd MAX). Those are more expensive ones, but I know expensive doesn't always mean good. Though, I know Sparrows has a good reputation. From what I understand, Petersen and HPC guard their metal secrets religiously.

Just to take an example, here are the yield properties for a few of the metals I'm considering.

1095 Carbon Steel - 379.2 MPa
301 Stainless Steel (1/4 hard) - Min 517 MPa
301 Stainless Steel (full hard) - Min 965 MPa
304 Stainless Steel - 215 MPa
316 Stainless Steel - 290 MPa
Titanium (Grade 1) - 170 - 310 MPa (not sure why it lists a range, but everyone seems to agree on it)

Assuming spring steel picks are usually 1095, and stainless are usually 301, does that mean I need relatively high yield strength? Would bad things happen if I used 304 stainless, say? What's a reasonable yield for lock picks? What are the other important properties, and what kind of numbers am I looking for? I have a conceptual understanding of some of the properties, but I have very little to use as reference as to what numbers make sense for a lockpick.

And if anybody has specific opinions on the metals from that list, go for it. I'd definitely like to know why as well.

Regarding heat treating, I know someone who can do it. No worries there.

[Joshua904]

You'd want grade 5 titantium. It's the most commonly used alloy version of titanium... A lot stronger too. I think grade 1 is just straight titanium with no extra.

[Joshua904]

At work, on my phone.. Can't see how to edit my last post. Got curious and looked the info up to make sure I was right (I had looked the info up a couple weeks back)

Snip from
https://en.m.wikipedia.org/wiki/Titanium_alloy

Generally, Ti-6Al-4V is used in applications up to 400 degrees Celsius. It has a density of roughly 4420 kg/m3, Young's modulus of 120 GPa, and tensile strength of 1000 MPa.[9] By comparison, annealed type 316 stainless steel has a density of 8000 kg/m3, modulus of 193 GPa, and tensile strength of 570 MPa.[10] Tempered 6061 aluminium alloy has a density of 2700 kg/m3, modulus of 69 GPa, and tensile strength of 310 MPa

[Jacob Morgan]

So I did check out 1095 steel. One thing that stood out to me is that it seems to have a higher yield strength than many forms of stainless. That surprised me. I thought stainless would probably be stronger in general. Or is it just that spring bends back more easily rather than breaking?

Keep in mind that yield and tensile may not translate well into how a pick resists flexing. Especially if heat treatment is involved. Heat treating modifies the crystalline structure of metal. Yield, tensile, etc. will be for the annealed state unless otherwise stated. Different alloys heat treat differently (or not at all). You either need to talk to a metallurgist or you could talk to a specialist at a steel distributor and see what they would recommend--but they may not want to spend time talking to someone go wants to make a batch of picks.

My suggestion would be to acquire a small amount of blue tempered 1095 and use that as a benchmark. It is already heat treated, so long as your manufacturing process does not over-heat the metal it is good to go.

If you want to do better than 1095 then experiment. At some point what works is what works, I'm a little skeptical that someone can pick the perfect metal for picks by looking up metallurgical properties in books.

Not all stainless steels are heat treatable, if I recall correctly. Titanium is light and corrosion resistant, but I'm not sure hat it would be the best for picks. There are some tool steels out there that would be really good, but may not be able to find them in strips.

Unless there is a published set of instructions for heat treatment of the alloy, or phase diagrams exist, heat treatment may be hit and miss. Also, depending on how the heat treatment is done, metal can form scale and and thin parts can warp. It is different than heat treating gears and milling cutters and such.

[PowerHaus930]

I'm not trying to hi-jack the thread but does anyone know where can I find strips of steel like the ones used for wiper inserts? The steel in non magnetic and from what I could gather the closest thing I could find similar to that is annealed 301 stainless steel. I couldn't find small strips at any metal suppliers online. Any help would be appreciated.

[GWiens2001]

I'm not trying to hi-jack the thread but does anyone know where can I find strips of steel like the ones used for wiper inserts? The steel in non magnetic and from what I could gather the closest thing I could find similar to that is annealed 301 stainless steel. I couldn't find small strips at any metal suppliers online. Any help would be appreciated.

You could always get ones from wiper inserts. They are frequently found around a car parts store, especially if it has been raining recently.

Gordon

[PowerHaus930]

I thought about that but I would feel a little awkward going around to auto parts stores and searching through the trash cans lol

[GWiens2001]

Just keep mumbling to yourself and growl at anyone who approaches you. You'll be fine.

You can also stop by and ask if they can keep them for you, as they frequently replace the wiper blades for their customers.

Gordon

[WestCoastPicks]

I'm not trying to hi-jack the thread but does anyone know where can I find strips of steel like the ones used for wiper inserts? The steel in non magnetic and from what I could gather the closest thing I could find similar to that is annealed 301 stainless steel. I couldn't find small strips at any metal suppliers online. Any help would be appreciated.

Auto wreckers will sell them for dirt. I pay $1 each for a wiper that has 2 24" inserts. But Also I've seen them go on sale new for like $5.
Street sweeper bristles are also good, walk the streets behind the street sweepers, you'll find a few. You can also ask your friends and family to save their old wipers for you. If you want something for nothing, you're gonna have to beg or dig in garbage cans. Parking lot garbage cans of big auto stores might be a great place to look. But I would prefer asking.

[Jacob Morgan]

The best way to pin down what wiper inserts or street sweeper blades are would be to have a lab test it with a mass spectrometer. That will give one the chemical composition and then one could look up what alloy it is close to. In addition to that, if one did a hardness test (like a Rockwell C hardness test) it would let one know what kind of heat treatment the item underwent.

I'm familiar with spectrometer tests on aluminum alloys, a sample has its oxide layer removed then the spectrometer "sparks" the clean metal and the machine analyzes it and gives a read out of the chemistry. There might be some independent labs and labs at colleges with material science programs that could test steel with a mass spectrometer. I'm not sure how thick a sample needs to be to be tested, that could be a problem with these materials?

[PowerHaus930]

I know about the street sweeper bristles however the only sweepers I have seen in my area clean parking lots of shopping centers and they seem to have nylon bristles not steel. I looked at some cheap new wiper blades but the inserts they had were not wide enough. I guess I was lucky when I changed the wipers on my car and I got what I think is the widest type of insert at about 3mm wide and the other wiper had 2mm inserts which are too narrow for making anything but tension wrenches. I guess you could make a hook from the 2mm strips if you bent one end of it up but they wouldn't be wide enough for making other types of picks with a higher profile like rakes. I guess I will go in search of some used wipers at the local auto stores. I would just go to a junk yard but there aren't any close to me. Thanks for the help everyone.

[PowerHaus930]

Sorry for double posting but i'm not sure how to edit a post. I watch BosnianBill on YouTube and he recently launched a website with a lot of information about locks and lock picking. I was browsing it and I came across some useful information on what materials to use for making picks. It looks like 301 cold rolled stainless steel is one of the best materials. He also talks about variations of spring steel and titanium. Check it out here - http://www.lock-lab.com/tool-zone/tool-quality/

[WestCoastPicks]

I know about the street sweeper bristles however the only sweepers I have seen in my area clean parking lots of shopping centers and they seem to have nylon bristles not steel. I looked at some cheap new wiper blades but the inserts they had were not wide enough. I guess I was lucky when I changed the wipers on my car and I got what I think is the widest type of insert at about 3mm wide and the other wiper had 2mm inserts which are too narrow for making anything but tension wrenches. I guess you could make a hook from the 2mm strips if you bent one end of it up but they wouldn't be wide enough for making other types of picks with a higher profile like rakes. I guess I will go in search of some used wipers at the local auto stores. I would just go to a junk yard but there aren't any close to me. Thanks for the help everyone.

The widest I've found is 3.8mmx1mm They are from dodge chargers/ challengers, 300's, Magnums and probably a few other of the same type car.
When walking through the auto wrecker (just got back from one) I look for larger cars, longer wipers, and when up close just quickly bend the tip of the wiper to expose the inserts to see what kind they are. I walked out of there today in about 15 mins with 10 wipers. Maybe my pickings are better here though.