Polypropylene Webbing Breaking Strength

How do you determine the breaking strength of polypropylene webbing? It depends. There is no industry standard way defining breaking strength. One manufacturer might test 10 samples and take the lowest strength. Another might take the average and a third might take the highest. Being a commercial grade product that is not designed for use in life safety or overhead lifting no government agency is telling the manufacturers what to do.

The industry has two basic models of polypropylene webbing, lightweight and heavyweight. American Cord and Webbing (ACW) has their 549 material that ranges from 0.040″ to 0.060″ in thickness and in a 1″ width has a minimum breaking strength of 360 pounds. ACW’s heavyweight material has a thickness range of 0.055″ to 0.075″ and a minimum breaking strength of 560 pounds.

I have seen lightweight 1″ material listed as having a 600 or even 700 pound breaking strength. Is one better or different from the other, probably not.

Brand     Thickness     Breaking Strength
ACW       .040-.060        360 pounds
S              .040                 500 pounds
TS            ?                      700 pounds
ECW       .040                 550 pounds

What makes piece of webbing strong is the amount of material (polypropylene in this case) it contains and how it is constructed. Thickness tells you something about the amount of material for a given width.

So how do you figure out what to use? First the webbing is usually not the weak point in a strap assembly. Stitching or buckles can be much weaker. A 1″ side release buckle will have a breaking strength of around 200 pounds, much lower than ACW’s 360 pound breaking strength for the webbing. If you have a critical application the only way to be sure is to make some assemblies and test them. If all you are doing is strapping up some sleeping bags, strength is not an issue.

With polypropylene webbing chafe and ultra-violet (UV) exposure are two issues which will weaken your strap. Materials like polyester offer much better abrasion and UV resistance along with a higher initial strength. If you are repeatedly loading a strap consider nylon whose ability to stretch might help dampen the load.

My article How Strong Is Your Strap covers sewing pattern choices. Searching the internet you can find other information that will be helpful but at the end of the day, build a prototype and test.

Nylon webbing

Straps to Go stocks 4 basic types of nylon webbing:

  1. Standard weight with a breaking strength of around 900 pounds for 1″ width material.
  2. Heavy weight with a breaking strength of around 2750 pounds for 1″ width material.
  3. Mil-Spec with a breaking strength of 1200 pounds for 1″ material.
  4. Tubular with a breaking strength of 4000 pounds for 1″ material.
Standard weight on the left, heavy weight on the right.
Standard weight on the left, heavy weight on the right.

The image above shows commercial grade webbing in both standard weight (on the left in light green) and heavy weight (on the right in dark green). Note that when I listed the breaking strengths above, I said “about” since these are not load rated goods.

Mil-Spec on the left, standard weight on the right
Mil-Spec on the left, standard weight on the right

Here we have Mil-Spec webbing in Coyote Tan and standard weight nylon webbing in green. You can see the construction is different and the Mil-Spec webbing has a breaking strength of 1200 pounds (this material has a design strength unlike the commercial grade products).

Mil-Spec on the left, standard weight on the right
Mil-Spec on the left, standard weight on the right

This gives you an idea of the construction difference between the Mil-Spec and commercial nylon webbings.

Tubular nylon
Tubular nylon

Tubular construction is the strongest of our nylon webbings. It is really two layers of webbing so you get a breaking strength of 4000 pounds in a 1″ width.

nylon-webbing-tubular

This view gives you a good idea of the amount of nylon used in the tubular construction which is why you get the added strength.

What is each type best suited for:

  1. Standard weight is great for tie downs and general purpose straps. It is used on backpacks for attachment points and it works well with single lock buckles and slides to allow for adjustment.
  2. Heavy weight nylon is used extensively for pet leashes and collars. It feels nice in your hand (this is why it is used for leash’s, not that you need the strength) or around your pets neck. We also sell it for heavy duty tie downs. We stock a wider range of colors in the heavy weight product than our other offerings.
  3. Mil-Spec nylon is used in the same way as the standard weight commercial product. It is a bit stronger but the trade off is in stiffness. If you are making MOLLE loops, this webbing would be a good choice.
  4. Tubular nylon is the climbers friend. Slings and attachment points are commonly made using tubular nylon. It holds a knot well and feels good in the hand.

If you have questions on what product would best meet your needs, give us a call at (253) 883-5800 and ask for Rollie.

Life raft container lashings

We can make life raft container lashings (tie downs) to meet your specific needs. Since our parent company, Westpac Marine, sells and services life rafts, container lashings are something we deal with every day.

2″ polyester webbing is the most common material we use however we also have urethane coated polyester webbing in stock just in case you need something that has a bit more grip.

Hardware is always stainless steel and we have shackles, D-rings, triangle rings, pelican hooks and snap shackles in stock meeting 90% of our sales. If you are looking for a real heavy duty product like the one shown above we might have a couple of day lead time to get the necessary components.

There is really no such thing as a standard lashing. Each is a bit different so everything we offer is custom although since we manufacture these in house, the lead time is usually one one day.

Give us a call at (253) 627-6000 and we will quickly fill your lashing needs.

Sail Ties

Straps to Go produces sail ties from both polypropylene and polyester webbing. The standard webbing width is 1″ although we can make them whatever width you want.

Construction

I am a bit “old school” and like to keep my sail ties simple. Just a length of webbing with a loop sewn in one end works for me. A bit better is to have the webbing in the loop twisted so that the eye stays open when you are trying to thread the other end through.

sail tie flat view

On the left you have a sail tie with a twisted loop, on the right (the black strap) the loop is not twisted.

sail tie side view

The side view shows how the twisted loop in the white sail tie stays open even if the loop has been pressed closed.

Others like to have a buckle on their sail tie, once adjusted all you have to do is snap is shut. We have had customers buy these ties in different colors so that they know that the blue ones are the longest, red are a a medium length and black are the shortest (or whatever colors suit your fancy).

The sewing on all of our sail ties is done using polyester thread with advanced UV protection. It is made in the USA by A&E and is a TEX 90 size. We use a Box-X stitching pattern.

Materials

Polypropylene webbing is the standard we use. It is inexpensive and doesn’t adsorb water which is also nice and comes in a bunch of colors. What polypropylene doesn’t like is sunlight. It will degrade if you don’t cover your sail ties with a sail cover.

Polyester webbing will stand up to ultra-violet exposure. It will adsorb a bit of water, more than polypropylene but much less than nylon. We only carry this webbing in black and white. Our white polyester webbing has a much better feel to the hand than the black so it would be my choice if I were replacing my sail ties.

Over the years I have sailed on boats with a bunch of different solutions for sail ties. The most basic, just a length of webbing with no eye works fine but is a bit more difficult to get secured than webbing with an eye in one end. Elastic cords were the rage for a while as was my black eye when I got hit from one of the plastic balls on the end of the cord. Then there were the contraptions that went from your mast to the end of the boom with a number of elastic ties hanging from them. Once you had these untangled and installed, the rest of the crew was cleaned up and in the bar.

Ordering

If you are looking for sail ties with a sewn loop, check out https://strapstogo.com/straps/sail-ties.php

If you want ones with side release buckles, https://strapstogo.com/straps/side-release-buckle-straps.php

In either case they will be promptly produced and shipped to you. We ship using Priority Mail which is speedy and only costs $7.00 no matter how many you order.

Questions? Give Rollie a call at (253) 627-6000.

ACW’s GM Series of Buckles

American Cord and Webbing is the manufacturer for the popular GM series of center release buckles. Originally designed for the military these buckles have found their way in to numerous uses both on land and at sea. We stock these in both 1″ and 2″ versions.

ACW 1 inch gm1 buckle
GM-1

As its name suggests, the GM-1 is designed for 1″ webbing. We stock it in black.

acw 2 inch gm-2 buckle
GM-2

The GM-2 which fits 2″ wide webbing is available in white. We have good inventory levels on both the 1″ and 2″ versions.

A while back I wrote about how the GM-1 buckle is used to restrain stern ladders on some Boston Whaler boats. The buckle is coupled with a short length of polyester webbing and if you need one of these, just give us a call at (253) 883-5800.

1″ Side Release Buckles

Straps to Go stocks side release buckles for 1″ webbing in many different configurations. All are manufactured by American Cord and Webbing (ACW).

acw 1 inch bar buckle
BSR

The BSR version is the most common found in the field. It is also the one buckle where there is a good possibility that different manufacturers components will work (how well is a different story) together.

acw 1 inch csr buckle
CSR

The CSR version is what we sell the most of today. It is a bit nicer looking than the BSR and the edges are rounded so stuff just might not catch on.

acw 1 inch double adjust csr buckle
Double Adjust CSR

The CSR buckle also comes in a double adjust version. With this buckle you don’t need to sew the webbing to the female half, you can just thread it through.

acw 1 inch bsr type 5 buckle
Type V

The Type V version of the BSR is primarily used on life jackets. It is larger than the standard BSR and a bit stronger too.

acw 1 inch curved bsr buckle
Curved BSR

Want to make a pet collar? Then the curved version of the BSR is just the ticket.

1 inch bsr buckles in colors
Colored BSR Buckles

Finally we stock the BSR model in a number of colors other than black. On the bottom is the popular coyote tan color, and we also have nylon webbing to match. Above that we have hot pink and bright orange both of which we have a limited supply at fantastic prices. One word of warning, the pink and orange colors will fade if left exposed to ultra-violet light.

If you need help making up your mind, give us a call at (253) 883-5800 or check out our full range of hardware at https://strapstogo.com

Is there such a thing as bad thread?

We received an order to produce a bunch of straps from polypropylene webbing. I loaded the sewing machine up with a fresh pound of polyester thread, wound a bunch of bobbins and thought I was at the start of a productive day. By the end of the day I was confused. Nothing was working right and I had spent the day trying to get my machine to sew. Thread tensions were checked, knives for trimming the thread were replaced, manuals were read and after work a cocktail or two were consumed. Not having long hair at least I didn’t have to worry about pulling it out.

Day two wasn’t any better and by mid-afternoon the frustration had really kicked in. I called my thread supplier and they informed me that their supplier had been having problems and I was not alone in having real issues. They gave me a credit for the bad thread and said they were changing suppliers and did not have a similar thread in stock which did a great job of raising my blood pressure. After some discussion we decided that the particular project I was working on would be just fine if I switched to nylon thread. The next day five pounds of thread came in the door and with great trepidation I wound bobbins and tried to make some straps. Lo and behold everything worked, stitching was fine, thread cut properly and my blood pressure returned to normal.

I was getting near the end of this project, the webbing straps were coming off the sewing machine but I was running out of thread. A quick call and I found that my supplier had received their polyester thread in the size and color I needed. The order was on its way and by the next afternoon I was winding bobbins and switching over. It was a nightmare, bad enough that I called the company who sold me the sewing machine a few years ago.

The fix was simple, well it should have been simple. The new thread suppliers product was small in diameter than what I had been using which required a different size needle. Good luck finding industrial sewing machine needles in Tacoma but finally I located one and was back in production. I also learned that a lot of the thread now comes from overseas and is very inconsistent. Upon asking what brand of thread the sewing machine company recommended I found that it was the brand my thread supplier had switched to, A&E which is still made in the US. It always feels good to support businesses based in the US.

So the answer to the question is yes, there is such a thing as bad thread. Quality control at the time of manufacture, age (that box grandma had might not work that well) along with storage conditions can all turn a good day into a nightmare.

Boston Whaler Stern Ladder Strap

boston-whaler-stern-ladder-strap

Are you looking to replace the strap that holds your Boston Whaler’s™ stern ladder? Straps to Go can make one for you.

The strap uses the GM-1 buckle from American Cord and Webbing (ACW) and some 1″ black polyester webbing.

The webbing is sewn to the female half of the buckle (left side of the picture above) and the male half is attached to the boat.

Give us a call at Straps to Go, (253) 627-6000 and ask for Rollie or order one online today.

Coyote Tan is here

Coyote Tan Side Release Buckle

We now have 1″ webbing and buckles in coyote tan. It’s hunting season and colors that blend in are required.

Coyote Tan ladder lock buckle
Coyote Tan nylon webbing

In stock are side release and ladder lock buckles along with nylon webbing that meets MIL-W-17337. As with all our goods we will sell 1, or 1 foot, up to as many as you need and they will ship for $6.00 via Priority Mail.

Check out our full line of Coyote Tan Products at https://strapstogo.com