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6mm accessory cord?


Original Post
Landon Stephan · · Unknown Hometown · Joined Nov 2017 · Points: 0

Hey guys,


I was taught making cordelette anchors and the guy teaching only mentioned using 7mm cord. 


I was able to pick up some 6mm nylon sheathed and nylon core accessory cord on sale at my local outdoor store and was wondering if you guys had used this size to make cordelette anchors or if it had to be 7mm to be safe. It would be used for rappel anchors and rope rope anchors only. No lead or trad. 


The specific I bought was 25 feet of https://www.bluewaterropes.com/product/6mm-accessory-cord/


What are your guys experiences with 6mm nylon acccesory cord for cordelette anchors? The weight rating of this cord seemed like more than enough, I just wanted to check in with some more season people  

Thanks!

Landon Stephan · · Unknown Hometown · Joined Nov 2017 · Points: 0

I know similar questions have been asked online, everyone speaks from 5mm to 9mm or various types or cord. Just trying to simplify things for myself, not drink from a waterfall and confuse myself, yet

Auden Alsop · · Baltimore, MD · Joined Jan 2017 · Points: 0

Should be fine, no way you should exert anything near 8.4kN toproping. I've used 4mm personally in the past, not necessarily recommended.

Vaughn · · Colorado · Joined Mar 2011 · Points: 50

Here's a nice concise synopsis of cord sizes used for cordelette:

Steph Davis Blog Post

Dave Furman
Hardgoods Category Manager
Mammut Sports Group, USA and Canada wrote: 
"if a nylon cord is used I’d strongly recommend using 7mm for anchor construction"

Jim Urbec · · sevierville, TN · Joined Jul 2015 · Points: 33

we climbed with a guide last month.  he had a "mini quad" made of sterling powercord.  think it's 6mm.  its a tecnora core.


https://www.instagram.com/p/BbW6HSkBJ8v/?taken-by=foxmountainguides


definitely cool application.



Brian in SLC · · Sandy, Utah · Joined Oct 2003 · Points: 14,479

Landon Stephan wrote:

What are your guys experiences with 6mm nylon acccesory cord for cordelette anchors? The weight rating of this cord seemed like more than enough, I just wanted to check in with some more season people  

Too small for me.  With a knot and a bit of damage from abrasion, you have a pretty weak situation.  7mm isn't that much bulkier and has nearly twice the strength.  Its also a whole lot more durable too.

jg fox · · Long Beach, CA · Joined Jun 2015 · Points: 5

The AMGA recommends a 7mm cord due to it's strength and possible improvement on durability. In fact they only teach with 7mm cord and I bet the guy teaching was student of one of their courses.  Will Gadd recommends 8mm instead for ice climbing.

http://stephdavis.co/blog/cordelettes-for-climbing/ - A little background on why 7mm is better.

But in your case, you are absolutely fine using 6mm if you do the following:

1. Inspect it before climbing. Look for worn out sheath and exposed core.

2. Limit shock loading situations (not a real issue if you are top roping).

Don't lose sleep over it and have fun top roping.

Landon Stephan · · Unknown Hometown · Joined Nov 2017 · Points: 0

Ok. I’m getting a few mixed reviews. For the ratings, but it “should be fine and safe”. I looked for 7mm but they were out, sadly darn sales!

Knowing this, I’ll probably use it tomorrow only. But I’ll set up another anchor with no cordelttle and clip it into the top rope as well ( separate from the cordelttle) with an extra locking carabiner. This way, I’m still getting the practice of setting up this anchor, but if something happens to the cordettle, we are still backed up. 

Landon Stephan · · Unknown Hometown · Joined Nov 2017 · Points: 0

Vaughn wrote:

Here's a nice concise synopsis of cord sizes used for cordelette:

Steph Davis Blog Post

Thanks for the link! This has great info! 

jg fox · · Long Beach, CA · Joined Jun 2015 · Points: 5

Landon, if you are close to an REI or sporting good store that sells climbing equipment, they should sell cordelette by the foot.  I would buy that instead of trying to find a deal on a precut bag.

If you really want to make bomber top rope anchors, buy some static rope, it gives you way more options for anchors.

Landon Stephan · · Unknown Hometown · Joined Nov 2017 · Points: 0

jg fox wrote:

Landon, if you are close to an REI or sporting good store that sells climbing equipment, they should sell cordelette by the foot.  I would buy that instead of trying to find a deal on a precut bag.

If you really want to make bomber top rope anchors, buy some static rope, it gives you way more options for anchors.

My local store had it by the foot, (that same stuff). It was on sale per foot (30 cents per foot instead of 50cent). Unfortunately, they are the only outdoor/climbing store close by. The closest REI is about 4h away. I’ll be near an REI in about two weeks while traveling for Christmas, so I’ll be able to stock up on everything then! 

Adrienne DiRosario · · Troy, NY · Joined Jan 2016 · Points: 0

As others have said, get 7mm for anchors. Use the 6mm for your prusik or autoblock. 

Gunkiemike · · Unknown Hometown · Joined Jul 2009 · Points: 2,785

jg fox wrote:

Landon, if you are close to an REI or sporting good store that sells climbing equipment, they should sell cordelette by the foot.  I would buy that instead of trying to find a deal on a precut bag.


If you don't want the store employees laughing at you behind your back, don't ask for "cordelette by the foot":. The material is not called cordelette; it's 7 mm nylon accessory cord.  A cordelette is one very specific thing you can make out of ccessory cord (of all sizes).

Christopher Smith · · Unknown Hometown · Joined Jan 2017 · Points: 0

Sounds like you are set on prusiks for life.  I suggest also giving some out to friends as stocking stuffers.  Get the 7mm, buy once cry once.

Alvin Tham · · Unknown Hometown · Joined Dec 2017 · Points: 0

I’ve a question. I bought a Tendon 7mm, 5m length ‘accessory’ cord. I also saw other brands in the store as well. Oh btw I bought it in the packaging in pre-cut to length. All these cord they always mention “not for climbing” I wonder why. They are indeed climbing brand. So can I still use it as anchor?

Mark Ra · · Frange, CO · Joined Feb 2014 · Points: 65

Cuzzo Italiano wrote:

I’ve a question. I bought a Tendon 7mm, 5m length ‘accessory’ cord. I also saw other brands in the store as well. Oh btw I bought it in the packaging in pre-cut to length. All these cord they always mention “not for climbing” I wonder why. They are indeed climbing brand. So can I still use it as anchor?

I believe this just means not for use as a dynamic climbing rope. The Tendon 7mm accessory cord does appear to be rated to 13kn for static use. 


Highlander · · Ouray, CO · Joined Apr 2008 · Points: 255

7mm tends to be the standard; if you want to go smaller choose one of the 5mm or 5.5mm tech cords out there that have similar strength specs as the 7mm nylon. 

David Kerkeslager · · New Paltz, NY · Joined Jan 2017 · Points: 55

The strength/durability of the cord is what matters, not the thickness (although strength and thickness are correlated obviously). Sterling PowerCords are very strong, so you can get a thin one that I feel safe hanging on. But I think I'd prefer to not put my weight on that BlueWater 6mm cord. 8kN is definitely enough, but as wear and tear happens on the cord, that doesn't leave a lot of margin of error.

Matt N · · Santa Barbara, CA · Joined Oct 2010 · Points: 278

I used 6mm Sterling, which had a slighter higher rating while still being nylon accessory cord. As long as it is always looped and the legs are doubled up, you're fine. I recently replaced mine with 7mm, though. 6mm will wear out faster (yet the nylon only version should age better than the fancy tech cords), so use it and replace it when needed. No need to repurchase now.  

Nick Sweeney · · Spokane, WA · Joined Jun 2013 · Points: 666

You'll probably be OK, but I personally appreciate the additional safety margin of 7mm.  I do use 6mm cord for V-threads and other rappel anchors.  

cmqr9001 Black · · Unknown Hometown · Joined Mar 2016 · Points: 135

I have a bit of a differing opinion on this. I use this New England 6mm nylon accessory cord bought from REI and it is by far my favorite cord to use because of how supple it is, easy to tie knots, and bites reall well as a prusik (better than 7mm in my opinion). The MBS is only 7.3kn, but assuming a typical 3-piece trad anchor, that’s 6 strands in the system for about a 44kn strength. Now the knot will probably reduce this by about 40% or so but that’s still puts it a around 26kn, and I tie in with the climbing rope. That’s plenty strong for me. If I come close to 26kn I have bigger problems to worry about, like why is my hip bone separated from my spine etc etc. 


https://www.rei.com/product/767610/new-england-6mm-accessory-cord-package-of-30-ft?CAWELAID=120217890000791500&gclid=CjwKCAiApo3SBRA4EiwAty8i-j4y-icq7N7oqHyWWQHRTjh2kL8ACRVBuU1qqCvcZnENJPsWgEF2IhoCH_MQAvD_BwE

Guideline #1: Don't be a jerk.

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