Confused about the numbers on the grippers

Question

I've got heavy grip 150lbs a long time ago, but was never able to close it. Some time ago I've got heavy grip 100lbs and I was able to improve my grip strength to the extend that I'm able to close 150 one after good warmup. I've ordered Captains of Crush 0.5 which is ranked 120 lbs, which should be in the middle.

But then come the surprise. I'm not able to close that thing even to the half (at least when I try with one hand). So now I'm totally confused, because it looks like CoC 0.5 ranked lower that HG 150, is actually much harder...

Is there an explanation for such feeling, or it's just a quality difference? And how should I approach that CoC beast? Doing many reps with HG 100, and then trying to close HG 150 as many times as I can, and first after I'm really confident with it, try to switch to CoC?

I'm able to close HG 100 about 40-50 times. HG 150 5, in best case 10 times. And CoC 0.5 even not up to half - and my finger joints really pain after trying.

Answer 1

The answer is that there is no standard for rating grippers. Unlike weights, which are very hard to argue, grippers have ratings similar to resistance bands. Do you rate them at the starting point, mid-way, the strength required to full-close?

It could be simply that the Heavy Grips 100 (100 lb) is the strength required to close and the Captain's of Crush (CoC) 0.5 (120 lb) is the strength required to start. We usually wouldn't know because this is a manufacturer's internal rating. It is also how brands get you to commit to their line-up.

From Iron Mind's CoC FAQ:

Q: My friend has a gripper that is supposed to be 150 pounds but it feels about like your Sport, which you rate at 80 pounds. What gives?

A: Your friend’s gripper may have been derived from a different testing system—or it might simply have a convenient number attached to it, without its really being tied to any specific test or measure. This is why you should not be surprised, for example, if a 195-lb. CoC gripper might be tougher to close than someone else’s “300-lb.” hand gripper, and why Captains of Crush grippers, rather than poundage numbers, are the universal standard for rating grip strength. Incidentally, we would peg an average sporting-goods store hand gripper at about 50 lb.

Now, I don't agree with CoC being the "universal standard", but they have the same idea that the testing systems to determine the ratings can be different. They've decided to try and move away from poundage and have you move through the levels.

Heavy Grips has a similar-ish statement on the linked page where they state:

Please note that different brands of hand grippers are not comparable in strength levels to the Heavy Grips. Heavy Grips test the "twisting force/torque" of the torsion springs and not lateral pressure.