Plain edge knife vs Seatbelt.

D

[digidude]

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Aug 21, 2005
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I know most people advocate serrated edges for emergancies, particularly when it comes to cutting seatbelts. My question is, can a plain edge blade do the same? Do serrations really make that much of a differance?
What do you guys think?


-[digidude]
 
Yes plain edges will readily slice seat belts, especially if the edge is thin and acute, and even more so if it is left at the optimal grit. Cutting seat belts doesn't take much of a sharp knife, you can easily cut the roof out of a car with a steel knife and then cut the seat belts inside without having to resharpen.

-Cliff
 
A serated knife, IMHO, will cut a seatbelt with less effort (important if you are self extracting after a wreck) than a plain edge. The plain edge will readily cut the belt if it is sharp, but benefits greatly from a slicing action whereas the serrated edge will cut on a straight pull through. Either will work, but I prefer serated for my safety knife. The spyderco assist is excellent.
 
I was an EMT in the early 90's and my knife was a Victorinox Swisschamp, it sliced through everything from seatbelts to leather boots and jackets without any trouble at all.
 
Very sharp, polished edges can slip and slide a lot on nylon web seat belts (and also on nylon rope). Plain edges sharpened with a coarser finish won’t slip as much.





- Frank
 
IMHO, a well-sharpened and well-maintained PE can do this specific task just as well as a SE. As proof, I offer my Spyderco SWICK in S30V, which is so (expletive-laden) SHARP, it's ridiculous!!!
 
If all you have is a plain edge and you hve to cut webbing, seatbelt, etc. you can always pierce it first and then continue the motion into a slice. Not ideal, but work with what you have. For Rescue and dive I carry one-handed (either fixed or folder) serrated blades because of minimum effort and minimum blade movement required.

P.S. The blades are back up for my primary cutter in either venue; trauma shears.
 
Ive cut the seatbelt out of a car with my kershaw blur. it didnt take much. in event of an accident you will probably have enough adrenaline to cut it in one slice.
 
I think an unmaintained serrated edge will cut a seatbelt better than an unmaintained plain edge. This may be an improtant factor for people who are not big on knife care.
 
I've used PE with zero trouble . My S.A.K cut a few its not much of a chore for any knife. I will add I've never had to "free" someone from a seatbelt. Any cutting i did was for my access and removal of pt. after being boarded.

Those belts that connect to the door frames get in the way.

As a rule i don't like knives used near PT.'s and not in crowded cars with recuers working in cramped areas etc.
 
I have cut several seatbelts on junkyard cars that were in my way harvesting parts. Any decently sharpened knife can do this. 420, 1095, 440c, Etc.. You don't need to have serrated edges to do this. If you let your knife get real dull then you are in Super Doo if you need to cut a seatbelt. If you can't maintain your knife then serrated is the way to go.
 
Knives can be a problem in close quarters, under stress. I'd been carrying a Spydie Assist (and still keep it handy) until I got a ResQMe for myself, my daughter, and her mother.

Dual function: 1) Blade cuts through jammed safety belts. 2) Spring-loaded head breaks side and rear automotive windows. Easily attaches to your key. A piece of safety equipment that is so convenient and affordable that every driver in your family should have one.​
 
That is really cool! I never thought of the windows for extraction but, does it work? Is it a onetime shot deal or can you reload the window breaker?
 
On the off chance that you've got unconscious passengers in a locked vehicle, you need to break enough glass fast to get to the door lock.

The ResQMe window breaker spring does reload. I don't know how many times the striker will work before it dulls, but as a short metal needle against glass it ought to last a while.

I got interested by reading EMTs and such who relied on them, rather than knives. The weight of the unit is negligible.
 
I feel the same way about knives around patients though I have bought a spyderco assist with the carbide tip. I have used EMT shears but the best thing I have found so far to cut seatbelts and clothes is my benchmade rescue knife. Works really great on everything I have cut. Pants, seatbelts, etc. Cuts like butta but does need to be resharpened after use. Worth it though. Keeps my patients safe and really exposes what I need to see fast and cuts through seatbelts and clothing quickly.

Benchmade model 5

KR
 
[digidude] said:
I know most people advocate serrated edges for emergancies, particularly when it comes to cutting seatbelts. My question is, can a plain edge blade do the same? Do serrations really make that much of a differance?
What do you guys think?


-[digidude]
Click to expand...


The strength of seatbelts is primarily tensile strength, which is the resistance to snapping or breaking by being stretched. It often relates very little to being cut or broken by perpendicular forces. Usually, the more tension is on something like cord, rope, seat belt webbing, the easier it is to cut that material. Some materials under tension can just be tapped with a sharp edge and then once the cut has been initiated the material will pull itself all the way severed.

Any moderately sharp plain edge should not have much problem cutting through a seat belt. To my knowledge, they are just nylon or some similar material, and not reinforced with any major crazy strong fibers, much less steel belts or strands.

-Jeffrey
 
Jeffrey, i agree, but keep in mind that a seatbelt that we need to cut is in a tight space, close to a person who may be injured already, perhaps even slumped over the belt in part. The scene may be tense and other dangerous factors like spilled gasoline may be present.

A Benchmade Rescue Hook or a ResQMe or other shielded seatbelt cutter will avoid the problems of an open, possibly pointed blade.
 
kr1 said:
I have used EMT shears but the best thing I have found so far to cut seatbelts and clothes is my benchmade rescue knife. Works really great on everything I have cut. Pants, seatbelts, etc. Cuts like butta but does need to be resharpened after use. Worth it though. Keeps my patients safe and really exposes what I need to see fast and cuts through seatbelts and clothing quickly.

Benchmade model 5

KR
Click to expand...

Although I am not in the business, I bought a Rescue Hook some time ago for the curiosity of it.

You mention sharpening it... How do you accomplish this? I have a Spyderco ProFile, a Sharpmaker, and a Ceramic Bench Stone... Nothing I currently possess is suited to sharpening that inner curved edge... What do you use? Is there a recommended sharpening device of any kind that Benchmade suggests?

-Jeffrey
 
I got a Mission sharpener that's a round and tapered rod with diamond coating. It would do fine for the Rescue Hook. For touch-ups, stropping would do. You could use a section of leather bootlace.
 
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