Failure test of homemade buckle

**Patrick** · 11-19-2007, 12:17

I'm not sure the scientific value of towing another car, but I very much like "see what happens" part.

The big lesson that I've taken away from this is that the forces required to mess up the line, much less the buckle, seem to be on a whole other level than we exert hammocking.

I'm leaning toward applying some measured weight to it next, but I don't have access to much. Between my friend and I, we might have 500 lbs of plates, but I'm sure that won't do anything.

**Rapt** · 11-20-2007, 10:28

The 700lb webbing rating is probably safe working load vs the 1200 lb failure load of the spyderline.

Sailing ropes strengths typically are FAILURE loads not safe working loads which would be usually a half to a third of the failure load depending on application.

**BillyBob58** · 11-20-2007, 10:51

That would be something good to know for certain, one way or the other. So all of this time I have been impressed with the superior rating for various ropes relative to their weight, and the whole time I was comparing apples to oranges? Apparently so. I thought they were both rated breaking weight, while buckles and such were rated "safe working load", which was 1/3 to 1/2 of the actual break point.

So if webbing is rated as "safe working load", that would mean Speer 1" polypro 700lb webbing has a breaking point of 1400-2100 lbs, and the Strapworks 1" polyester 3500 lb would be expected to break at 7000 to 10500lbs? If so, WOW! But some how I don't think so, but I certainly don't really know.

Does anybody here know how these various ropes, webbing and devices are actually rated, breaking strength or safe working load? The last I heard, rope and webbing were rated at the breaking point while devices ( hitchcraft, buckles, etc) were rated for safe working load. Is this incorrect?

**Rapt** · 11-20-2007, 11:18

You have to check the specs provided for each and if its just a number without clarification its not terribly useful. I'd wager that the 1" Speer is a 700 lb working strength, but the 1" Strapworks is 3500lb breaking strength.

Many webbing tie downs and tow straps give both numbers... and yes they're usually 1/3.... I have seen 2" webbing tow straps with failure strengths in the 25-30 THOUSAND pounds range...

I do know that most of the time sailing ropes strengths are given as failure strengths.

So that would be an easy explanation why the rope failed before the webbing... There could be other less obvious answers...

The short answer is you have to check each on a case by case basis. A number alone means little, but is often used for marketing.

**BillyBob58** · 11-20-2007, 11:43

Thanks. And I wouldn't be surprised if Speer uses a more conservative rating.

**Patrick** · 11-20-2007, 11:51

There's a thread around somewhere about a guy breaking his Speer webbing. I want to say it was right in the middle, but I don't remember for sure. That's the only time I remember hearing of that, which seemed to be the common sentiment.

I've always felt that my biggest enemy is wear, which is one of the reasons I switched to the buckle and ring. My tree huggers (homemade Speer webbing) were mutated all to hell from the line being lashed to them and that was that fat blue Byer rope. Probably had less than fifteen nights on them and they were all smushed and melty looking. Seemed to me like if something was going to fail, that's where it was going to happen.

**BillyBob58** · 11-20-2007, 11:58

And there have indeed been a number of recent HH hugger failures at that exact point. At Neo's hangout, Skinnybadger's huggers looked bad after the first use. Mine still look reasonable after a year of occasional use.

**Cannibal** · 11-20-2007, 12:02

Originally Posted by Patrick

There's a thread around somewhere about a guy breaking his Speer webbing. I want to say it was right in the middle, but I don't remember for sure. That's the only time I remember hearing of that, which seemed to be the common sentiment.

I think that was slowhike. But he also said he was hanging with a pretty long span from tree to tree; not a normal hang.

**TiredFeet** · 11-20-2007, 16:50

Just looked on the strapworks web site under FAQs. Quoting their site:

*Q: What is the strength rating I need?

*A: A strap's overall strength is limited by its weakest point. This can be the webbing or it can be the buckle. You need to understand that there are "breaking" strengths and there are "working loads". The breaking strength is where the webbing or the buckle will actually fail under a static load (a dead lift, for instance). On the other hand, working loads are a recommended maximum load to use considering other factors like impacts, shocks to the strap from dropping or jarring, etc. Most manufacturers recommend 33-50% of the breaking strength as the actual working load (we figure at 50%). If your buckle is rated at 1000 lbs, and your webbing is rated at 500 lbs, you have to figure your working load as 50% of the webbing's rating, or 250 lbs. Our cam strap webbings are rated as follows...Lightweight Polypropylene-600 lbs; Heavyweight Polypropylene-900 lbs; Flat Nylon Webbing-3500 lbs; and Polyester-3500 lbs.

That seems to indicate that they think webbing is rated at breaking strength.

**warbonnetguy** · 11-22-2007, 11:13

Originally Posted by Rapt

I'd wager that the 1" Speer is a 700 lb working strength, but the 1" Strapworks is 3500lb breaking strength.

nope, both are breaking strength. heavy wt polypro has a breaking strength of 700-800# per inch of width depending on where you get it. that means 2" would be 1600# and 1/2" would be 400#

the strapworks is 3500# is the break strength as well.

i haven't seen any webbing rated on a safe working load, except everything sold at home depot or walmart etc...

line is only stronger than webbing for it's weight b/c you can get line made from spectra and vectran. webbing usually comes in polyester/nylon/polypro, which is all weaker # for # than high tech fiber. this is the main reason, i'm sure there is some strength difference between a 12 strand braid and a webbing weave, but the main difference is from the fiber it's made of.