Axial test?

It was a year or two ago, that the question came up. It was on a Reference Librarians' Stumper Research List. "What would be the average or representative force needed to crunch a fresh coconut?"

The recherche', the exotic: it is their meat and potatoes. But unexpectedly, there was no recorded data in existence.

(I do not use the phrase "In Existence" unadvisedly. St Petersberg to Washington to Oxford - there is no repository that escapes attention.)

So finally, as a question of honor, I purchased coconuts and two wooden joists, gathered a floor scale and some outsize nuts and bolts, and turned in an answer - in the hundreds of pounds.

In the question of pull out force of commercal wall anchors, I suspect that a technical section reference librarian could turn in a response to you in milliseconds, if not sooner.

But in case the spirit of enquiry (inquiry?) is not dead in your breast, you might possibly consider a steel tee section with a strategic hole or two, a support beam to form the fulcrum on the wall, and a spring scales for reading the force with which you lever out the fixing.

Or if this is too like engineering, why not call the maker of a wall anchor system, and ask for representative pull out force on their offerings? (Some of them even have this intelligence marked on their products....) Not to mention: Google. There! I said it.

Regards

Brian Whatcott Altus OK

Hi, Brian,

You purchased some coconuts.....?

Thanks for taking the time to reply. The problem I have is that whatever substrate is available for me to drill and fix into - be it concrete, wood, brick, cob (straw & mud!), render, etc etc would be different and I would need to know for that particular application so would like to test each individual fixing, especially if I were to send somebody else to do a job and they would be relying on that fixing. Even if I knew the manufacterers guidelines I could never be sure that the particular substrate that I was fixing in to was in the same (good) condition as when they did their tests. As I mentioned I have tried google, but its quite hard to know what to put into the search? 'pull out test' or 'fixing test' or ''hilti newton testing' or 'force test meter' or what. As I said the only thing I came up with was 'axial test' and wondered if anyone had any more info on this.

Cheers Stuart

stuart wrote in news: snipped-for-privacy@d4g2000prg.googlegroups.com:

The thing you are looking for is called a force ga(u)ge, and consists of a chuck to take a variety of terminations, a spring balance and a pair of handles.

Think fish-scales. You probably won't want to buy a proper force gauge.

Alternatively you can hack something together with a cable, a pulley and a large container and some water.

Cheers

Greg

If you wish to provide a fixing that is proof against material variability, then this is what you do. Drill two holes (probably 1/4 in or 3/8 inch would suffice) clear through the wall, and mount a backing plate on the far surface which is held by bolts or threaded rod though the holes you made. This is proof against all but a bodily pull out of the wall section containing the backing plate.

Next?

Brian W

snipped-for-privacy@d4g2000prg.googlegroups.com:

Perfect. Thanks very much.