As a (semi) professional sailor I have a ton of experience with Spectra/Dyneema (same thing). We use Amsteel (and other brands of) dyneema for many, many purposes these days. It has completely replaced wire rope on modern sailboats, and is starting to replace more and more steel components on boats (shackles, turnbuckles, etc).
A couple comments:
Amsteel advertised "average breaking strength" is conservative. When we've destructively tested brand new Amsteel it tends to break at much higher than the rated strength--often close to twice the strength.
Amsteel does not appear to degrade appreciably in the sun. I'm sure it will eventually, but we do not consider it to be something that needs replacement simply due to UV exposure. It is considered an acceptable substitute for wire lifelines, which live in the sun constantly. We use it to attach mast rigging (instead of turnbuckles) where it lives in the sun constantly. These are very critical applications, yet UV is not a factor for replacement (only chafe).
Amsteel loves being used at high percentages of its breaking strength. We commonly use it at or near the rated strength, and I've never seen it break except due to chafe.
Amsteel will lose its color (fade), and will "fuzz up". Both of these are acceptable. The manufacturer (Sampson) advises that it should be replaced when it loses 25% of its bulk.
And of course, Amsteel doesn't kill you or other people around when it breaks, and can be handled without leather gloves...
It truly is a wonder material. You should feel confident using it. 5/16" or 3/8" is your choice based on winch size, but don't feel you need to go "oversize".
It also turns out that spectra is extremely chafe resistant, and to prevent chafe on lines, the best thing to use is.... spectra. But chafe is the enemy of synthetic lines, so don't let the line get cut through by sharp metal.
HOWEVER: Spectra has one weakness, which is that it loses strength at a relatively low temperature (around 270F). Not typically a problem for truck winching, but worth keeping in mind (ie, don't let it touch engine or exhaust parts).
A couple comments:
Amsteel advertised "average breaking strength" is conservative. When we've destructively tested brand new Amsteel it tends to break at much higher than the rated strength--often close to twice the strength.
Amsteel does not appear to degrade appreciably in the sun. I'm sure it will eventually, but we do not consider it to be something that needs replacement simply due to UV exposure. It is considered an acceptable substitute for wire lifelines, which live in the sun constantly. We use it to attach mast rigging (instead of turnbuckles) where it lives in the sun constantly. These are very critical applications, yet UV is not a factor for replacement (only chafe).
Amsteel loves being used at high percentages of its breaking strength. We commonly use it at or near the rated strength, and I've never seen it break except due to chafe.
Amsteel will lose its color (fade), and will "fuzz up". Both of these are acceptable. The manufacturer (Sampson) advises that it should be replaced when it loses 25% of its bulk.
And of course, Amsteel doesn't kill you or other people around when it breaks, and can be handled without leather gloves...
It truly is a wonder material. You should feel confident using it. 5/16" or 3/8" is your choice based on winch size, but don't feel you need to go "oversize".
It also turns out that spectra is extremely chafe resistant, and to prevent chafe on lines, the best thing to use is.... spectra. But chafe is the enemy of synthetic lines, so don't let the line get cut through by sharp metal.
HOWEVER: Spectra has one weakness, which is that it loses strength at a relatively low temperature (around 270F). Not typically a problem for truck winching, but worth keeping in mind (ie, don't let it touch engine or exhaust parts).
