What's the difference between Accessory Cord and (Semi-)Static Rope?

What's the difference between Accessory Cord and (Semi-)Static Rope? In general it seems that accessory cord is available in smaller lengths and diameters, but assuming you had two lines each of 60m/9mm but one was accessory cord and the other static rope, what would be the difference?

Looking specifically at BlueWater, they sell 9mm static rope and accessory cord and the differences look like:
- Elongation: the accessory cord has ~3x the stretch of static rope
- Strength: the static rope has ~40% higher tensile strength
- Weight: the static rope weights ~20% more than the accessory cord

Are these universal properties of all similar accessory cord vs static rope matchups, or just these two from this brand? Does this mean accessory cord is actually more like semi-static rope, and if so, is there any difference between semi-static rope and accessory cord? Are there other factors that are involved like sheath proportion or certification standards or anything else? Please help. I'm struggling.

The BlueWater links I looked at are here:
- https://www.bluewaterropes.com/product/9mm-accessory-cord/
- https://www.bluewaterropes.com/product/9mm-spec-static/

Just a guess, but I think items sold as static rope has to conform to some standard (like EN 1891) that is not applicable to cord.

kind of unrelated to this topic but -

I'm looking to build my own via feratta lanyard and would like to use 7-8 mil accessory cord over trying to find 10' lengths of climbing rope or cutting my glacier or double rope for it.

Do some accessory cord brands or types stretch more than others?  Do they have a % stretch somewhat close to a dynamic rope that would be a safe(ish) application for a via feratta lanyard?

I'm guessing I should use a 7 or 8 mil dynamic rope or better just buy a via feratta lanyard.

Bluewater offers a 'dynamic' 7mm cord for prussiks.

splitclimber wrote:

kind of unrelated to this topic but -

I'm looking to build my own via feratta lanyard and would like to use 7-8 mil accessory cord over trying to find 10' lengths of climbing rope or cutting my glacier or double rope for it.

Do some accessory cord brands or types stretch more than others?  Do they have a % stretch somewhat close to a dynamic rope that would be a safe(ish) application for a via feratta lanyard?

I'm guessing I should use a 7 or 8 mil dynamic rope or better just buy a via feratta lanyard.

Unless you have some sort of energy dissipator built into your lanyard, even a "fully dynamic" cord is not up to the high-fall-factor falls possible on a VF.

splitclimber wrote:

kind of unrelated to this topic but -

I'm looking to build my own via feratta lanyard and would like to use 7-8 mil accessory cord over trying to find 10' lengths of climbing rope or cutting my glacier or double rope for it.

Do some accessory cord brands or types stretch more than others?  Do they have a % stretch somewhat close to a dynamic rope that would be a safe(ish) application for a via feratta lanyard?

I'm guessing I should use a 7 or 8 mil dynamic rope or better just buy a via feratta lanyard.

Does it matter? Falling 12’ on 3’ of rope is gonna hurt no matter if it stretches 5% or 35%.

splitclimber wrote:

I'm looking to build my own via feratta lanyard and would like to use 7-8 mil accessory cord over trying to find 10' lengths of climbing rope or cutting my glacier or double rope for it.

Don't do this.  Via ferrata lanyards may be subject to fall factors greater than two, which no climbing rope—much less accessory cord—is rated for.  Special energy absorbers are required in this application.  At least get a Kong KISA and use an approved rope with it.  

Just call bluewater, why would you ask a bunch of random internet people? They're more than willing to answer questions, they're pros in the industry and they actually have correct info and know what they're talking about.