Speaking of home wood-related repairs...

[Chris Friesen]

Sorry for the delay...the heat treatment keeps it from being brittle from work-hardening when the threads are rolled.

Chris

[Chris Friesen]

That's why I specified "properly heat-treated". The heat treatment keeps it from being brittle due to work-hardening from rolling the threads.

Just for fun, I tried your experiment with a #10 Spax brand exterior screw. (Lee Valley carries them.) The screw bent. I then pounded it back straight and removed it with a power driver.

I then tried it with a #10 "Precision" brand decking screw from Home Depot. The screw snapped.

Chris

[J. Clarke]

You're confusing impact strength with shear strength.

[-MIKE-]

I'm not. It relates enough to get the point across.

I've seen the tests, I've sat through the lectures.

bye

[HeyBub]

Shear strength of a 16d nail is 150 pounds

http://74.125.113.132/search?q=cache:jPPGP54rgrEJ:

means if you hang your tool belt on a nail in the wall, you will break the nail.

[J. Clarke]

Yes, you are. You may think otherwise but what you think and what is true are not necessarily the same. When you hit something with a hammer you are testing its impact strength--this is exactly the technique that is used in the laboratory, with the velocity and mass of the hamner and the point of contact carefully standardized (your experiment does neither). When shear strength is measured a steady load is applied.

If you know anything about metallurgy you'll know that when you harden steel you increase its tensile and shear strengths and reduce its impact strength.

When you talk about "shear strength" you are using a technical term which has a specific meaning, and the test that you describe does not measure that quantity no matter how mucg you may want it to.

What tests and what lectures?

[RicodJour]

Right...if you're wearing the belt at the time.

R

[-MIKE-]

And it would still hold you.

[fftt]

Mike-

I know all about "those giant machines".......I ran a research lab for nearly 20 years, we had one.

And there is NO WAY a single 16d name can do ANYTHING that involves

16,000 lbs other than be destroyed at a WAY lower number.

You're latest post is mostly nonsense. :(

cheers Bob

[fftt]

I've been looking through some of my textbooks and publications, but don't have any more time to look.

[fftt]

l break the nail.

[fftt]

Mike-

If these tests & lectures were involved in process that lead to a technical degree (physics or engineering)....please let me know so I can notify your alma mater to begin the "degree recall process".

You have, in the later part of this thread, violated "the first rule of holes"..........which is "stop digging".

shear & impact tests are used to determine different properties....

btw find that 16,000 lb number yet?

cheers Bob

[-MIKE-]

Cool. Any idea what it can take?

[-MIKE-]

Bob, I heard you the first time. Do you know what the number (lbs) is, since you ran the tests?

[DanG]

There are fairly rare occasions when the sheer value of a nail is necessary to know. I was given the number 90# in sheer for a 16d box nail once when it really did matter, this number was from a structural engineer who I am sure had quite a safety factor in his figures. Of course, common nails are higher.

[RicodJour]

[fftt]

depends on the loading conditions & assembly

an ultimate number or an allowable (like a working load) number?

allowable in timber like ~100lbs

ultimate load in timber, probably 400lbs

ultimate load in a test machine...depending on the steel condition / alloy; maybe 800+ lbs

cheers Bob

[Richk]

Ok - I'll chime in . . Structural Engineer, with degrees and official License who has designed many buildings.

the 90# for a 16d box nail is about right on . . to start with. There's a lot of factors that could increase or decrease that number by a factor of two or so depending on exactly what's going on and what kind of loads you are holding up (for example:short duration loads like wind, multiply by 1.6; hot, wet conditions might be multiplied by about 0.6 or so)

Steel strength for get's pretty meaningless since it's wood that always fails in a proper joint, but the minimum steel yield strength for both nails and wood screw is 70,000 psi to 100,000 psi. Neither nails or screws are usually heat treated.

Rich K

[-MIKE-]

I'm not talking about working loads or allowable anything... I never was.

I'm talking about the weight requite to shear (tear off like being cut, or whatever the proper scientific terminology is) a 16d nail.

Is that what that 800 number is? Can you point me to any video.pics on the web that show the machine/test.

[-MIKE-]

This was never the issue, nor what I was referring to. I was speaking of the weight required to shearing off the nail.

Can you explain this more?