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Tree Reaper

Sewing cinch straps

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I want to stitch a 10,000 lb. cinch strap, what thread and where can I purchase this thread?

Thanks.

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If this dude is going to hold 10,000 pounds, . . . how wide and thick is it going to be?

May God bless,

Dwight

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Don't. That's my advice. Buy a rated/tested/approved strap. Logging is deadly enough as it is, without guessing if a home-made strap will hold or not.

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Dwight;

The straps webbing strength is 10,000 but the working limit is 3300lbs.  The strap is 1/16" thick by 2 " wide.

These are not for resale but my own non critical personal use and I'm well aware of load limits.

I'm just looking for the proper thread to use in my CB4500.

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How many layers are you putting together, . . . or are you talking about sewing straps end for end to make a much longer one?

May God bless,

Dwight

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Spectra webbing and thread are used in some high strength factory  -made climbing slings and runners. It is stronger than nylon, however has very little stretch, which is a big disadvantage in a dynamically loaded situation, such as taking a fall on a piece of pro attached with spectra webbing. Also, the slings I have used were put together with multiple bar-tacks, but this may possibly be a manufacturing expedient. I believe you can find a lot of technical discussion about webbing construction over on the parachute forums, those guys have very specific specification about what they build. It's possible that you might get Russ Walling over at Fish Products to talk to you about what he uses to make his climbing gear (best on the planet) but he might just see the big red "liability" light go on. 

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Nobody ( with any sense ) is going to say anything which ( should anything go wrong at any time with a strap that you make ) might come back to bite them..blame always looks for something / someone, to stick to..and then there are lawyers, who for a cut of the proceeds, will try to make anything stick to nothing, and ruin everyone in the process.

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10 hours ago, Dwight said:

How many layers are you putting together, . . . or are you talking about sewing straps end for end to make a much longer one?

May God bless,

Dwight

Just a loop on one or both ends.

Found it, http://www.coatsindustrial.com/en/products-applications/industrial-threads/dabond

Edited by Tree Reaper

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Hopefully I'm too far off to be sued but make sure if your stitching webbing that you don't use any leather point needle as it will cut and weaken. A point only style I'd recommend.

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13 hours ago, Tree Reaper said:

Dwight;

The straps webbing strength is 10,000 but the working limit is 3300lbs.  The strap is 1/16" thick by 2 " wide.

These are not for resale but my own non critical personal use and I'm well aware of load limits.

I'm just looking for the proper thread to use in my CB4500.

Don't let me assume to tell you how to run your railroad, . . . but the devil would be handing out ice cream cones before i would lift 3300 pounds with a 2 inch wide Walmart belt, . . . which is what you are advocating here:  1/16" by 2" wide, . . . is nothing more than a 4 oz strap. 

Scary !!!!!!!!!!!

May God bless,

Dwight

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9 hours ago, RockyAussie said:

if your stitching webbing that you don't use any leather point needle as it will cut and weaken

Now that's beneficial information, thank you.

Let's not assume I'm using these for any critical applications.

My working slings and ropes are the best .

I was given these straps because they didn't have eyes, they could be used for securing brush or small trailer loads of lumber, hold a refrigerator to a hand cart among other things.

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TreeReaper, if you've never looked at his site, Robert VanNatta, retired logger and attorney, has great information on current, retired and antique equipment his family has used on their property in Oregon. Very articulate writer, not sure if he is still active as the site has not been updated in a long time. I particularly liked his discussion of their M123A1C tractor, logging is probably one of the few useful things you can do with a tractor with a gcvw in excess of 100,000 lbs.

http://www.vannattabros.com/index.html

IMG_0645.JPG

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I have heard of VanNatta through Gerald Beranek (High Climbers and Timber Fallers).

I have webbing slings and use them occasionally but my primary slings are loopie and whoopie made from Tenex.

These straps were purchased new and still are but without eyes for reasons unknown to me.

Without at least one eye they are pretty much useless, even as a tie down.

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You should contact Service Thread - they will be able to help you get the correct thread for any heavy project. 

 - You may also need a hammer.  haha love this video

 

 

 

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Further evidence of the old adage that there's not much that can't be solved by using a hammer!:lol: (Nice machine too).

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I have several hammers in my sewing machine tool collection.

 

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I've made contact with Service Thread, thanks for the information.

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I don't think it's a big deal. If I'm not mistaken, automotive seat belts are supposed to be built to withstand loads of 6000-7000lbs., so that's an easy point of reference for all of us. Seat belt webbing is about the dimensions of the webbing you describe and their stitching is there for all to see. Coats specifies Tex 270 or 400 which would be 277, 346 or 415 in our usual thread sizes.

But look at the small number of stitches on a seat belt, I think one could easily match or exceed that strength with a greater area of smaller stitches in smaller thread. Design your slings so that there are no loads trying to peel the eyes apart, over-stitch them, keep an eye on chafe and don't use them in any critical applications and you shouldn't have any problems.

I've designed, sewn and tested lots of climbing harnesses and made plenty of lifting slings and I don't think I've ever seen stitching fail. Be conservative and design with 2X any expected load in mind. Also, if you sew black webbing with white thread or white webbing with black thread it's a lot easier to keep an eye on the condition of the stitching in use.

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5 or 6-cord, nylon thread, equal to or greather than A-A-59826 Type 2 Class B. A-A-59826 supersede the older VT-295E spec. Pay close attention to the way your sling will be loaded with regard to the splits or joints for the eye's. Please have a look at the linked PDF for some interesting technical reading. 

http://www.dtic.mil/dtic/tr/fulltext/u2/110406.pdf

 

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Great information, thank you.

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  Back when I worked for the airlines, just for fun we made up a test sample using passenger seat belt components to do an experiment with a tester used for testing the  pull strength of cable assemblies.   Passenger seat belt webbing is identical to automotive seat belt material.   Surprisingly, the metal fittings broke before the webbing did.  I don't remember the exact tension that we went to, but it was well over 10,000 pounds when it failed.   We used a standard passenger buckle and end fittings in the experiment.   Webbing is amazingly strong !!

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