Stainless vs. Spring Steel

[markracer]

I was just monkeying around today with a master padlock and a snake made by Peterson's. As I was dilligently working away, the tip broke off in the lock. I thought I was being somewhat gentle-guess not:(

I know a lot of you prefer spring steel due to its ability to flex more. However, I'm finding the spring stuff to be somewhat brittle by nature. I prefer the Peterson handles (plastic/rubber) over SouthOrd's metal. To make a long story short, I would like for Peterson to start using stainless steel with the option of rubber and plastic handles. I feel with this combination would provide much better durability in the long run. Plus the stainless won't rust like spring steel!

Just my two-cents:) What do you guys think???

[CaptHook]

Unless there was something wrong with the pick before hand, I think you were monkeying a little too hard.....
Spring steel in picks such as petersons, is a very good quality, very forgiving material. By forgiving I mean it is alloyed and tempered to have very good malleability. Personally, I prefer spring steel to stainless, but its all subjective.
Chuck

[Romstar]

Um, aren't your Peterson picks molly steel? I know most of mine are.

If you broke a pick, there are a few options.

1. Too much pressure on the pick.
2. Defect in the material.
3. The pick was made against the grain of the steel.

One of the reasons I prefer HPC over just about anything is because they only cut the picks in line with the grain. Yes, even steel has a grain.

If your grain is opposed to the direction of the tool, it will be more likely to break.

If I had to guess, I would say option 1 or 2 are your culprits. I don't think I have broken a pick in years. The two I remember breaking from use were made by me, and broke because I overheated the steel while making the pick. My fault, my consequence.

Now, if you'll excuse me, I have to cut some new plastic handles. I have an idea I want to try out.

Romstar

[CaptHook]

Rom, its possible theres molybdenum in the alloy, but not Im not positive. Either way, I want to correct your terminology..... Metals have a crystalline structure, "packed" depending on the method of shaping(ie casting, rolling, drawing, forging,etc also dependant on the purity level of the metal itself). Cast metals, such as iron used in cheap weightlifting weights, show larger "crystals" when looking at a broken edge, they are almost visble to the naked eye. Rolled steel such as the material used for pick making, shows a denser structure that you would need to view under a microscope to see.
I said all that to say this, I think Roms number 1 suggestion is the culprit. Im guessing you accidently twisted it or something while in the keyway.
Chuck

[Romstar]

I had this huge post written up about the composition of stainless steels, and the way the crystaline structure does in fact grow into a grain. Then, I did something wrong, and the post disappeared.

How that grain is modified after the steel is formed by heat treating, or tempering. Why some stainless steels cannot be heat treated, but some can be hardened by cold process. The differences between hot and cold forging, tempering, annealing and hardening.
How each of these processes changes the physical characteristics of the steel by modifying the granular structure.

The difficulties in welding certain stainless steels, and why the problem exists.

The use of mollybdenum in steel, and how it creates a type of stainless commonly refered to as duplex stainless.
Different types, including Martensitic, Ferritic, Austenitic and Duplex.

There was a lot of stuff. Anyway, here it is in a nutshell I guess. I know I am missing some stuff, but anyway....

As a molten metal cools, atomic forces begin to pull or force the atoms into solid particles called nuclei, which take on specific and identifiable crystal structures. Because the nuclei have the metal's crystal structure, additional atoms join the nuclei. As these nuclei get bigger, they form grains. This orderly arrangement of the atoms is called a lattice.

But as the metal solidifies and the grains grow, they grow independently of each other, which means eventually these different areas of growing grains have to meet. When they do, the arrangement of the atoms in the grain structure is disrupted at that meeting point. This is called a grain boundary. Grain boundaries form a continuous network throughout the metal, and because of the disrupted structure at the boundary, the metal often acts differently at the boundary locations.

Despite the addition of alloying metals to a base metal, the conditions are the same. The benefit of the alloy metal is that it enhances the strength or some other characteristic of the original metal.
Steel is nothing more than low carbon content iron. Stainless steel is alloyed with Chromium, and this material creates a barrier that makes the steel passive in the presence of other materials such as oxygen.

Treating the steel, either in a heat manner, or by cold forging depending on the alloy results in modifications to the granular structure of the steel. Typically creating a finer granular structure. As a consequence, the crystaline lattice is further refined and aligned in the desired manner. This can mean softening, hardening, tempering or some other combination of desired traits.

After all is said and done, the raw steel stock used by pick companies has a particular granular arangement. Stamping, grinding, or cutting against this grain can cause the stress of using the pick to be distributed along the narrow cross section of the pick rather than longitudinally from the tip to the heel of the pick as intended. This results in a tool that will eventually fail from metal fatigue.

There, now don't tell me I never taught you anything.
Romstar

[Guitar_J]

How do you know all this stuff?!

[Chucklz]

I'm sure Romstar would agree with me..... but simply put, NEVER pass up an opportunity to learn.

[logosys]

I'm sure Romstar would agree with me..... but simply put, NEVER pass up an opportunity to learn.

Romstar, can you come teach my ENGR 213 class? You put in that post what he took an entire class period to try to explain.

[Kung]

i have had the peterson snake rake break off in a lock to and right after i paid for the sucker. made me mad

[CaptHook]

Rom is indeed an intelligent person. He also likes to debate things.
Rom, I speak from 13 years experience in metal work that has included sheetmetal, foundry casting(and hot rolling), welding, machining(conventional, and several types of CNC including EDM). I grew up in a steel mill town, that supplied Detroit with a good majority of metal through the 70s & 80s. I may not speak in the textbook terms that would suit a scientist, but I feel I have a knowledge of metal that textbooks cant cover, experience.
Im thinking by your last post that we are on the same page, just different terms. "Grain" as you are speaking is a cluster of crystals. That suits my purposes. Heres a new term for you though, "flow". Refering to the flowlines of the steel as it is rolled. This is the longitudinal packing of the metal crystals as it is drawn or rolled. It is what accounts for metal bending better in one direction than another, this is what creates the grain structure you speak of.
Rom, Im not flaming, far from it. Im very glad to meet someone with a level of knowledge I do not possess, that is after all how people learn. I think you have the scientific knowledge, please accept I have the manufacturing knowledge.
Handshake????
Chuck

[Romstar]

No problem at all CaptHook. You pretty much nailed it on the head though. I do seem to debate a lot. I think one of my biggest problems comes from terminology.

Yep, the packing of the crystaline structure does indeed create the grain I was referring to.

As you pointed out, the direction of the flow creates a situation where the metal bends better in one direction that the other.

This as you know is very important in metal stamping. Whether it's stamp cutting or press forming. Following the grain or flow is a very important aspect in forming metal parts.

In press forming, going against the grain can result in actually tearing the sheet metal. This is one of the reasons why parts with large depths such as deep bowls are normally pre-heated before pressing. I have seen such items cold formed, but I think they were a different type of steel with a higher degree of ductability.

Mostly the rest of that rambling was for everyone else. I think the Capt has way more experience than I do in forming steel and working it.

Now, I just have to find a place that will make me some decent stamping dies to cut picks. I'm getting swamped by orders lately.

Romstar

[Romstar]

Guitar_J I know all this stuff because as Chucklz said, never stop learning.

Logosys, as far as teaching goes, I don't think I have enough knowledge to do that. Although at one time I did want to become a teacher. Although I almost shudder at the thought of warping more minds to think like me.

As for Kung's difficulty, I have to wonder just how many other people have had problems with the peterson picks.

Oh, and Hook, I forgot that handshake. Sorry about that. Gladly accepted.

Romstar

[logosys]

Guitar_J I know all this stuff because as Chucklz said, never stop learning.

Logosys, as far as teaching goes, I don't think I have enough knowledge to do that. Although at one time I did want to become a teacher. Although I almost shudder at the thought of warping more minds to think like me.

As for Kung's difficulty, I have to wonder just how many other people have had problems with the peterson picks.

Oh, and Hook, I forgot that handshake. Sorry about that. Gladly accepted.

Romstar

Well, see that's the beauty of it, my professor doesn't seem to have enough knowledge to teach it either!

[Romstar]

If I were going to teach anything it would be computer science, or locksmithing and security.

Those are the two things I am best at it seems.

Even then, I just don't think that I have the credentials to become a teacher anywhere. I never graduated university.

Romstar

[CaptHook]

See, theres the catch 22, you have the knowledge, and the clear ability of passing it along, you are a wordsmith my friend. But theres a slip of paper holding you back.
The trade school I went to offered me a job as an instructor in the machine shop, but first I needed 5 years on the job experience as a machinist. After I had it, the school (state run) was transfered to be under the direction of the university, which said you need a teaching degree.
So now I have moved and moved on and run liquor stores. Steel......Budweiser....Steel.......Budweiser...... not too different
Chuck