Tension Testing - It is official!!! According to Instron there is such a thing as tension testing

[ireload2]

Instron is one of the leading tensile testing machine manufacturers on the planet.
They make a living building machines that are used for every day tension tests in engineering and quality labs.
Perhaps our members that do not believe there is any such thing should read the introductory page for tension testing at the Instron home page. The Instron logo consists of 2 stylized stick figures pulling a piece of test material.

Tensile Testing

What is Tensile Testing?
A tensile test, also known as tension test, is probably the most fundamental type of mechanical test you can perform on material. Tensile tests are simple, relatively inexpensive, and fully standardized. By pulling on something, you will very quickly determine how the material will react to forces being applied in tension. As the material is being pulled, you will find its strength along with how much it will elongate

http://www.instron.us/en-us/our-company/library/test-types/tensile-test

 

[jerseyjoe]

We tension test every heat treat lot where I work (aluminum impact extrusion).

It's a requirement in order for us to keep all the ISO and TS certifications and requested by our customers..

 

[Ron Blain]

My concern with tension is uniformity. If I were to pull a bullet using an applied tension, for example using a collet type bullet puller, I would expect to see a curve if I plot it. There will be a breakaway tension being the force needed to start the bullet dragging out of the case mouth followed by the force required to continue to drag the bullet out of the case mouth. If I did this using a constant force applied uniformly what I figure I want to see is uniformity from cartridge to cartridge. I have given some thought to doing this but never managed to build a test fixture.

Ron

 

[Alex Wheeler]

The issue with all of this "engineering" talk is it may or may not apply to shooting. Too often very smart people will overlook or refuse to try or test things because in their field it just shouldn't work. Well, in shooting you test everything and if it works you do it. Engineers can sometimes be their own worst enemy in this sport.

 

[Lapua40X]

The portion of your post that surprises me is "Perhaps our members that do not believe there is any such thing" ... A fella named Leonardo Da Vinci was working with tensile strength calculations before a fella named Columbus took a boat ride across the Atlantic. Are there really people at this time in history who missed that class?
However, with respect to ballistics, I suspect we are more interested in release force (frictional force) than tensile strength.

" ...in shooting you test everything and if it works you do it"

- I kinda like that philosophy.

 

[Bart B.]

Engineers can sometimes be their own worst enemy in this sport.

Engineers can sometimes be your best friend in this sport. They're the ones who established military small arms bullet's release (extraction) force specifications.

 

[dmoran]

Engineers can sometimes be your best friend in this sport. They're the ones who established military small arms bullet's release (extraction) force specifications.

What do those specifications do for handloaders, competition shooters, hunters, and plinkers?

 

[BoydAllen]

Engineers can be indispensable....but they tend to think that because they have a "hammer" that every thing is a nail, or that because their calculations are complicated that they have visualized the problem correctly. All in all, the guys that are the best that I have seen at solving on the ground, get the job done sorts of problems have not been engineers. On the other hand when you need one, nothing else will do.

 

[Ned Ludd]

Given the amount of weeping, wailing, and gnashing of teeth over the units used to describe neck tension, I have decided that of everyone ever DOES agree on a single convention, I will then purposely start using something different...just for fun, you understand .

 

[dedogs]

I will then purposely start using something different

You won't have to, fguffey will do it for you! dedogs

 

[Bart B.]

What do those specifications do for handloaders, competition shooters, hunters, and plinkers

those specs only tell what the military established.

Measuring their bullets' release force enables them to reveal another variable in their ammo that changes muzzle velocity. They should learn that less with a smaller spread enables lower ES and SD numbers

 

[ireload2]

They do nothing for people that do not understand how to use data.
I

What do those specifications do for handloaders, competition shooters, hunters, and plinkers?

 

[ireload2]

Apparently you have not worked in a real engineering environment. That is where people put stuff on ICBMS, send hardware to Mars, design integrated circuits, design and manufacture medical implants, design and build jet fighters and all the other things that non-engineers take for granted because all many of them know is to hit the start button.

Engineers can be indispensable....but they tend to think that because they have a "hammer" that every thing is a nail, or that because their calculations are complicated that they have visualized the problem correctly. All in all, the guys that are the best that I have seen at solving on the ground, get the job done sorts of problems have not been engineers. On the other hand when you need one, noting else will do.

 

[BoydAllen]

You make my point. All of those tasks have almost unlimited resources at their disposal. The people who calculate and design do not build, and if you ask the ones that do, there are always practical problems to be solved that fall outside of the engineers experience and skill sets. I admire engineers, but if you only had engineers on any of the projects that you mention, with no other help, they might come to appreciate how important the rest of the team is. Of course that will never happen. In shooting, the problems that we generally have to solve do not require the wonderful applied mathematical and visualization skills that engineers have. Often a more direct approach is better, but I have often seen where someone with an engineering background, who is used to having the whole team and budget available try to turn a simple problem into something much more complicated than it has to be. Buildings are not ICBMs, but ask any builder about engineers, or architects. It take the whole team, but quarterbacks have their egos.

 

[dmoran]

They do nothing for people that do not understand how to use data.
I

Think many understand data well enough, just that there is a lot of useless and/or irrelevant data that doesn't apply to actual accuracy improvement or consistency on the targets. Then there is those who know data well, but not how to apply it to anything but theory and/or internet replies.

 

[KMart]

You make my point. All of those tasks have almost unlimited resources at their disposal. The people who calculate and design do not build, and if you ask the ones that do, there are always practical problems to be solved that fall outside of the engineers experience and skill sets. I admire engineers, but if you only had engineers on any of the projects that you mention, with no other help, they might come to appreciate how important the rest of the team is. Of course that will never happen. In shooting, the problems that we generally have to solve do not require the wonderful applied mathematical and visualization skills that engineers have. Often a more direct approach is better, but I have often seen where someone with an engineering background, who is used to having the whole team and budget available try to turn a simple problem into something much more complicated than it has to be. Buildings are not ICBMs, but ask any builder about engineers, or architects. It take the whole team, but quarterbacks have their egos.

+1 on Boyds comments. A fine example is the auto industry. Engineers design and bring on line new automobiles all the time. The end user is left with a product where they have to deal with safety recalls and pattern failures, (transmissions, engines, and computers) for as long as they own the vehicle. The engineer goes home, has a shower and a cold beer.

 

[ireload2]

Many times relevant data cannot be recognized without a regression analysis. In order to perform and understand a regression analysis you need a background in statistics of at least one introductory class. A course in designed experiments is also useful. If you do not have that background I would expect you to make exactly the kind of statement that you made.
In theory, theory and practice are the same.
In practice they are not.

Why would you try to define who knows data and who doesn't when you clearly don't know what you are talking about?

Think many understand data well enough, just that there is a lot of useless and/or irrelevant data that doesn't apply to actual accuracy improvement or consistency on the targets. Then there is those who know data well, but not how to apply it to anything but theory and/or internet replies.

 

[ireload2]

I bet you don't know what you are talking about because you have never been an engineer and you have never brought a product on line. Anyone that has been an engineer would not make such a general statement. Furthermore you apparently don't understand that marketing and management dictate many of the constraints that limit manpower, budget, research and testing of a new design. You are blaming engineers for the cost cutting goals that come from management's desire to make a bigger performance bonus.
For example many automotive engines do well to last 150,000 miles when a diesel truck engine can easily last much longer. The ability to make a very long lasting engines had been around for more than 50 years. It is not the fault of the engineers if management wants to sell engines with a limited oil sump capacity just to cut down on the number of quarts of oil that roll out the door in the crankcase.
On top of that you apparently cannot tell the difference between design issues and manufacturing defects. Often they appear to be one and the same. Without conducting failure analysis you may not know. I have seem many surgical instruments fail due to incorrect materials and heat treat. I have also seen many that failed because the surgeons beat them to death.
Sometimes stupid customers don't take care of and maintain their car properly. One of my high school acquaintances blew up his 375 Hp 396 Chevelle engine drag racing it - twice. He got 2 new short blocks installed under warranty. Do you really think poor engineering caused that?

+1 on Boyds comments. A fine example is the auto industry. Engineers design and bring on line new automobiles all the time. The end user is left with a product where they have to deal with safety recalls and pattern failures, (transmissions, engines, and computers) for as long as they own the vehicle. The engineer goes home, has a shower and a cold beer.

 

[Bart B.]

The people who calculate and design do not build, and if you ask the ones that do, there are always practical problems to be solved that fall outside of the engineers experience and skill sets.

Always? Sounds like someone thinking all groups fired will be the same size as the first few-shot one.

A blanket statement not big enough to cover the whole bed of humanity.

Typical remarks from someone who probably has never worked with engineers who calculate and design then build and test and finally correct things and rebuild them to perfection. Or is jealous because they don't have the skills and knowledge to be one.

Of course, some are that way. Just like folks who are not engineers that cannot solve problems outside their skills and knowledge.

 

[ireload2]

Wow you are really wrong. No projects anywhere has unlimited resources. It never has and it never will. It is always controlled by management and in the case of a consumer product it constrained by marketing too.
Since you are an outsider there are always problems that will fall outside of your ability to comprehend if you don't work in the industry. Anyone on the outside looking in is just a fish in a bowl. You really don't have a clue how many intelligent people have contributed to the success of everything around you.
You have strange ideas about teams as if you have never worked on one. Ever hear of concurrent or simultaneous engineering? How about DFX. I bet not. Ever managed a project using PERT or CPM? Probably not. How about critical path analysis? No again I bet... I have worked with some of the top engineers in the country. It is apparent that you haven't. I have worked directly with many design engineers to insure that producibility is designed into new products from the very beginning. You should look up Mil Handbook 727 Design Guidance for Producibility. It is a 60 mb document that provides guidance for the entire organization for reducing costs and improving performance of new designs. Some of the products that I worked on are examples in that document.
Ask anyone about a building and you will never hear it called high tech. jajajajajaja. Sorry but there is no comparison. I have been on manufacturing floors where semiconductor equipment is assembled where there is over $100 million of work in process at any given time. Those machines include cryo pumps, microwave generators, ultrahigh vacuum systems, magnetic couplings, robots, computer control systems, deadly process gases, high voltage power supplies and other features that will kill people if you make a mistake in the design.

You make my point. All of those tasks have almost unlimited resources at their disposal. The people who calculate and design do not build, and if you ask the ones that do, there are always practical problems to be solved that fall outside of the engineers experience and skill sets. I admire engineers, but if you only had engineers on any of the projects that you mention, with no other help, they might come to appreciate how important the rest of the team is. Of course that will never happen. In shooting, the problems that we generally have to solve do not require the wonderful applied mathematical and visualization skills that engineers have. Often a more direct approach is better, but I have often seen where someone with an engineering background, who is used to having the whole team and budget available try to turn a simple problem into something much more complicated than it has to be. Buildings are not ICBMs, but ask any builder about engineers, or architects. It take the whole team, but quarterbacks have their egos.