Military-grade 550 will have a minimum of 7 strands in the cable. As such, cordage will usually be slightly larger in diameter than commercial counterparts.
The main distinguishing mark of the mil-spec paracord is that one of the strands inside will be color-coded. This is required by the military for quality control purposes and specifically for each manufacturer.
Military-grade nylon paracord cords will also be made of high-quality nylon, 100 percent. Nylon is weather resistant and won't rot in humid conditions like other materials.
The commercial level paracord will have two or three strands inside, which may or may not be wired. Cable ties make the cable stronger, but there is no way to verify this without dissecting a paracord.
While it is possible for unscrupulous overseas manufacturers to add strands in dummy color codes to make their products look military-grade, this is more expensive to produce and most inexpensive imitators will not do such a thing.
The material used may be nylon, but often polyester. Be skeptical of any cables not produced in the United States.
Lower quality paracords will have noticeable deviation along the cable. Lumps, protuberances, and vertices in which the inner strands are joined together are an indication of the inferior cord.
To date, very few retailers have sold the same paracord used by the American military. Before you buy, check the paracord for quality control problems. If buying online, contact the retailer to make sure you get what they are advertising.
Remember, just because a paracord is produced by a certified government contractor doesn't mean it's the real thing.
The 550 military-specific paracord is stronger, more durable, and far safer than the commercial class, making it a true asset in an emergency survival scenario.