r/searchandrescue • u/Whatthedillyo85 • 26d ago

CMC RESCUE Carabiner strength question

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I’m having a hard time figuring out how strong this is.

What would it be rated to in poundage?

Thank you ahead of time for the assistance.

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u/F1r3-M3d1ck-H4zN3rd 26d ago

kN and pounds measure different things, so you'll never have a perfect conversion. Newtons measure force, while pounds measure weight - but you can say that with a static load a 255lbs weight create 1kN of force - though things get more complex when there is dynamic loads. Drewts86 already gave a good explanation, I thought I would just throw in the reason that you are having trouble finding an exact conversion.

16

u/LazerBear924 Fire/Mountain Rescue, CO 26d ago

Thats not accurate. Weight is a force, just a very specific type of force caused by gravity acting perpendicular to the Earth.

Pounds are the US customary system unit for force. Engineers use pounds to measure forces in any dimension as needed in structural design, as forces are forces. Source: am a licensed civil engineer and rope rescue tech.

2

u/speckyradge 26d ago

Ok now I'm confused (metric educated person now living in the US). What is the US customary unit for mass? Metric weight would be in N (mass x g) with mass expressed as kg. People tend to use the word weight when they're really talking about mass as you're pointing out. So if US pounds are equivalent to N, what is equivalent to kg? If you're doing F=ma without using metric, what unit is used?

6

u/LazerBear924 Fire/Mountain Rescue, CO 26d ago

Formally mass in the USCS system is the slug, equal to 1 lb-s2/ft, or 32.17405 lbs on earth or 14.59390 kg.

Basically we use pounds for both and just say pounds-force or pounds-mass (lb-f // lb-m).

7

u/F1r3-M3d1ck-H4zN3rd 26d ago

I still hate the imperial system but I will hand it to ya'll that "the slug" is a phenomenal unit name.

Edit to add: gunna start using the word "slug" and when coworkers ask me what it means I'm gunna call them commie euros who need to learn American units.

2

u/speckyradge 26d ago

That's fascinating, thank you.

3

u/Quatermain 26d ago

If you want to be even more confused, the 'pound' in the US that is used as a weight and measure is officially defined as 0.45xxxxx kg.