Breaking vs. Working, kN vs. Lbs

So when I buy safety rated climbing gear it will always be rated in kN and this will be the breaking strength?

Most GOOD Quality Climbing Gear will have its rating posted or stamped on it. Slings and similar equipment have rating in the range of 22kN (Kilo Newtons)to as high as 30 or so. Some Metal Carabiner can be as rated as high as 50 kN.
A kN is around 220 lbs so a 23kN gear is rated at around 5060 lbs

\"One kiloNewton (kN) is the force required to change the inertia of a mass of a little over 220 pounds. Simplified, a piece of gear rated to one kN will hold 220 pounds. A carabiner rated to 24 kN will hold about 5,000 pounds.\"
Copied form this posting:
http://gorp.away.com/gorp/activity/climb/expert/exp071801.htm

Them you have also info on:
WLL= Working Load Limit ( Maximum Safe Loading for something)
and ABS= Average Breaking Strength ( What force it takes to break it apart)
The Sherrils Catalog has charts for these numbers and how they are measured.(Page 55)
Order one they are FREE from http://www.wtsherrill.com/home.asp

oldtimer wrote:

WLL= Working Load Limit ( Maximum Safe Loading for something)
and ABS= Average Breaking Strength ( What force it takes to break it apart)
The Sherrils Catalog has charts for these numbers and how they are measured.(Page 55)
Order one they are FREE from http://www.wtsherrill.com/home.asp

Thanks. That is what I need to do -- read some catalogs and spec sheets.

Davej wrote:

oldtimer wrote:

WLL= Working Load Limit ( Maximum Safe Loading for something)
and ABS= Average Breaking Strength ( What force it takes to break it apart)
The Sherrils Catalog has charts for these numbers and how they are measured.(Page 55)
Order one they are FREE from http://www.wtsherrill.com/home.asp

Thanks. That is what I need to do -- read some catalogs and spec sheets.

Rec tree climbers generally follow the \"no less than 22kn\" rated gear for climbing. Working tree climbers are required by ANZI guidelines to use 23kn or better. The European standard for working tree climbers is 22kn. You have to ask, \"What's a 1kn difference?\" That's why many U.S. rec climbers are ok with 22kn. The average working load as I understand it is the average adult male weight x2 (to cover rescue situations) multiplied by 15 (to cover shock loading scenarios). That number should come to less than 22-23kn depending on your personal minimum kn preference. It's probably way overkill but we like it that way, feels much better when you're hanging high on a skinny bit of rope.
-moss

I guess I was trying to get at two questions:

-If a 'biner is rated in kN does that generally imply it is life-safety rated?

-Is 23kN the expected breaking point of a 'biner marked 23kN ?


Thanks.

Davej wrote:

I guess I was trying to get at two questions:

-If a 'biner is rated in kN does that generally imply it is life-safety rated?

-Is 23kN the expected breaking point of a 'biner marked 23kN ?


Thanks.

To the first question: No. Just because it has a kN rating, that doesn't mean it is rated for life safety.

Rec climbers GENERALLY adhere to the 22 or 23 kN number, but not very strictly. Actually, I wouldn't say we're adhering to the rule. I think what is really happening is that the gear we want for all the OTHER reasons just happens to be stronger than that 22kN mark.

My lanyard has a breaking strength of 4,000 pounds

Regarding your second question. Yes, if it is stamped 23kN, it means that is the ABS (or perhaps the MBS- Minimum Breaking Strength) of that item.

Desi- I like the point that you made about most good gear makers marking their hardware. I'm always skeptical of a company that is scared to put their name on their hardware. I like to see who made it so that I can ask them a question if I have one later. Don't buy gear that isn't marked!


love
nick

There's an online converter for converting KN to pounds here: http://www.unitconversion.org/force/kilonewtons-to-pound-forces-conversion.html

22kn, at about 4945lbs, falls just short of the 5000lb minimum for many strength requirements in the US.

22kn, at about 4945lbs, falls just short of the 5000lb minimum for many strength requirements in the US.

Even thou most REC Climbers try to use properly rated gear similar to what is used in Arboriculture work. There is not actually any \"requirement\" in the US for \"REC Climbing\" so the above quote is not exactly right without that small caveat.

We use several slings, lanyards, pulleys and other products that are not rated at 5000 lbs but I am confident that they are safe for our climbing activities when used correctly. If someone wants to use only gear rated at 5000 lbs plus that is Ok with us also.