Calibration Of Grippers

[Carlos F. Rivera Pagan]

Hello:

I have seen for a while many people telling about that they have calibrated there grippers and that i.e. a #3 is around 150 - 160# and the #3.5 is around 170 -180# and #4 is more than 200#.

I saw once a person put a gripper on a vise and hang some weights from the top of one of the handles. Is that what they call calibrating a gripper?

Before I started grip training I bought Baseline Hand Dynamometer and my best shot at it, consistently (before grip training) was 160#, both hands. I could close the #2 the first time I tried but in the #3 had like 15mm - 20mm gap to close it. Once I got close the #3 I was in 195# in the hand dynamometer. I tried a different hand dynamometer (different motion, the one that has the kg ratings like half a circle) and grip 188#, not so far from the Baseline Dynamometer.

So when I start to see that calibrated grippers saying that a #3 is 155# or like 3.08 well I really dont understand that kind of ratings base on my previous ckecks from my hand dynamomter. If when I start I has gripping pressure of 160#, consistently why then I couldn't close the #3?

By the way right now I can hit the 100kg number from the other hand dynamometer with my left hand and still 2-3mm to go on the #3.5.

So from my perspective I think that the calibration of that grippers has something missing. Maybe is where you applied the weight loads in the handle of the gripper. Maybe instead of putting the band on the end of the handle, people should put the band of the weightload where the middle and ring fingers are supose to be in the handle, in order to get a more real lecture or calibration of a gripper.

I hope to contruct a calibration machine soon to see if I can make my own test on grippers.

Hope you understand my english since is not my first language, spanish is my first language.

Don't hesitate to comment about the topic. Thanks to all.

[Cannon]

Hey Carlos, lots going on here

You're right, the calibration process that most are using is to hang weight over the END of the handle until they touch. It produces pretty consistent and repeatable results, but there is variation to be sure.

The calibration numbers obtained in this manner would have no correlation to the "ratings" on the grippers from the manufacturer or numbers that you would pull on a dyno.

The best comparison is exactly what you stated. Having tried both, "Once I got close the #3 I was in 195# in the hand dynamometer." That's the best comparison you can ask for.

Also, regarding the calibration numbers, the conversion to a 1-2-3-4 scale is arbitrary. The more useful information is the actual calibration number. The conversion is obtained by randomly deciding that a #3 is 150 (or whatever) and a #4 is 209 (or whatever) and therefore a gripper in between the two would account for a percentage of the difference. For example, the difference in the numbers above is 59 pounds so a 170 gripper would account for 20 of those 59 pounds. 20/59=.34 so a 170 gripper would be 3.34. Totally arbitrary.

The end of the handle is used because it makes the weight lower. Less to lift. It also gives a concrete point of reference. Not all grippers have middle bands, but they all have ends of handles.

The calibration process is not perfect to be sure.

Good questions!

[tselegala]

the calibration is just to compare one gripper to another and not to determine the force required to close it. The reason people do this is to see if they have a hard or easy #3 for example, because grippers vary. And also to compare some other brand of gripper to say COC grippers. To determine the amount of force to close the gripper would vary not only according to the gripper but also on how big you hand is where you hold it etc...better just to standardize. A dynanometer is best to determine what your actual max hand strength is.

edit: we posted in the same time MAtt did not mean too just repeat what you said.

Edited June 30, 2010 by alexis

[chop163]

The end of the handle is used because it makes the weight lower. Less to lift.

Anyone who has calibrated anything that's a #3.5 or above will agree with the importance of keeping the weights as low as possible. Trying to hang 200 odd pounds off the end of of a #4's handle is difficult, time consuming and dangerous enough without bumping the weight up another 100 pounds by hanging the weight on the middle of the handle.

[Carlos F. Rivera Pagan]

Hey Carlos, lots going on here

You're right, the calibration process that most are using is to hang weight over the END of the handle until they touch. It produces pretty consistent and repeatable results, but there is variation to be sure.

The calibration numbers obtained in this manner would have no correlation to the "ratings" on the grippers from the manufacturer or numbers that you would pull on a dyno.

The best comparison is exactly what you stated. Having tried both, "Once I got close the #3 I was in 195# in the hand dynamometer." That's the best comparison you can ask for.

Also, regarding the calibration numbers, the conversion to a 1-2-3-4 scale is arbitrary. The more useful information is the actual calibration number. The conversion is obtained by randomly deciding that a #3 is 150 (or whatever) and a #4 is 209 (or whatever) and therefore a gripper in between the two would account for a percentage of the difference. For example, the difference in the numbers above is 59 pounds so a 170 gripper would account for 20 of those 59 pounds. 20/59=.34 so a 170 gripper would be 3.34. Totally arbitrary.

The end of the handle is used because it makes the weight lower. Less to lift. It also gives a concrete point of reference. Not all grippers have middle bands, but they all have ends of handles.

The calibration process is not perfect to be sure.

Good questions!

the calibration is just to compare one gripper to another and not to determine the force required to close it. The reason people do this is to see if they have a hard or easy #3 for example, because grippers vary. And also to compare some other brand of gripper to say COC grippers. To determine the amount of force to close the gripper would vary not only according to the gripper but also on how big you hand is where you hold it etc...better just to standardize. A dynanometer is best to determine what your actual max hand strength is.

edit: we posted in the same time MAtt did not mean too just repeat what you said.

Fair enough answers. Thank you to both of you.

Alexis: Totally understandable the thing about the comparison of how big your hand is and where you hold the gripper. If I put the #3 really near my fingers I can close it far further since I have my #3 filed, but if I tried to TNS, wich the end of the handle is set far from my fingers I can barely close the #3. That definitely answer some of my questions that I had of the calibration comparison hand dynamometer tests.

Have anyone before tried to calibrate a gripper hanging the weights just a little bit more up that the end of the handles? Just for curiosity. I imagine is difficult but, anyone?

[BillEinstein]

I have a friend who has calibrated quite a few grippers and he said that for the heavier grippers, coc 2.5 and up, you can add about 3 lbs. per millimeter as you go towards the spring from the end of the handle grip.

If you measure from the beginning of the coc handle band it's about 45 mm to the handle's end, which means it will take approx. 135 lbs more force to close from there than at the end.

So if a coc #3 is calibrated at 150 lbs. by RGC method, then adding the 135 lbs. will give 285 lbs. total, which is real close to the 280 lbs the company rates it's #3 at.

Also this means that if you are able to close the #3, depending on how much your pinky hangs off the the end and how thick your ring finger is, you should be able to pull between 190 - 200 lbs on a hand dynamometer. Which by your pulling 195 at the same time as closing the #3 proves.

[Carlos F. Rivera Pagan]

I have a friend who has calibrated quite a few grippers and he said that for the heavier grippers, coc 2.5 and up, you can add about 3 lbs. per millimeter as you go towards the spring from the end of the handle grip.

If you measure from the beginning of the coc handle band it's about 45 mm to the handle's end, which means it will take approx. 135 lbs more force to close from there than at the end.

So if a coc #3 is calibrated at 150 lbs. by RGC method, then adding the 135 lbs. will give 285 lbs. total, which is real close to the 280 lbs the company rates it's #3 at.

Also this means that if you are able to close the #3, depending on how much your pinky hangs off the the end and how thick your ring finger is, you should be able to pull between 190 - 200 lbs on a hand dynamometer. Which by your pulling 195 at the same time as closing the #3 proves.

Really helpful, thanks a lot my friend.

[Carlos F. Rivera Pagan]

Where I want to go with this topic is to have something to compare (information) with grippers and hand dynamometers. Like in example: if a person can close a #3 he should be around 188 - 200# in a hand dynamometer and if he can close the #3.5 he should be around 210 - 220# in a dynamometer.

I saw Gabriel Sum with the Robert Barbaran Grip Tester wich is a hand dynamometer test himself and put 106kg or 234#. I assume that for closing a #4 a person has a grip pressure of around 105 - 110kg or more than 110kg perhaps, because everybody here know that Gabriel is really close to get the #4. (link:

)

My best thru last weekend is 215-220# with my left hand and 210-215 with my right, and I'm about 2-3mm to close the #3.5 so I assume that a someone needs to be in 220 - 225# in a dynamometer in order to conquer the #3.5.

That's my reason for the topic. Hope everybody understand.

[Cannon]

This is just my opinion, but I think the only way to accomplish what you want is to have a bunch of people who know their max calibrated gripper close all squeeze the same dyno and see what they get. If it's different dynos and any given person's opinion, the info won't be worth much. I just don't think there is a useful way to make the comparison except what you've already done. Squeeze both and give an opinion.

[BillEinstein]

The best comparison I've seen is between the coc grippers and the static, no movement, baseline dynamometer pull.

Different grip settings on the dyno relate to different parts of the coc gripper close.

But if you put your baseline dyno on it's first setting (the crush), from what I've seen if you're able to pull about 100 pounds less than what ironmind has their grippers rated at, ie. you pull 180 on the dyno, then you will be able to close the 280 lbs. rated #3.

Other gripper companies must measure force in different ways, because this really only holds true for the coc grippers I've seen.

[Hubgeezer]

The best comparison I've seen is between the coc grippers and the static, no movement, baseline dynamometer pull.

Different grip settings on the dyno relate to different parts of the coc gripper close.

But if you put your baseline dyno on it's first setting (the crush), from what I've seen if you're able to pull about 100 pounds less than what ironmind has their grippers rated at, ie. you pull 180 on the dyno, then you will be able to close the 280 lbs. rated #3.

Other gripper companies must measure force in different ways, because this really only holds true for the coc grippers I've seen.

There is a person on the Gripboard, he does not post often, "Oldtimer". His name is Dale Harder. He may have the largest collection of Hand Dynometer readings of strong people, athletes, and members of this board than anyone in the world. Not exaggerating. I have no idea how generous he would be in sharing it, as he has a newsletter that he publishes, and it costs money. I don't think he has ever covered in an "extensive" manner the different "dyno" numbers, and I don't know what kind of shape his data base is, but he is a retired math teacher, so he is wired into numbers like you would not believe. If you ask him, he might be open to sharing some information in this thread.

[Carlos F. Rivera Pagan]

This is just my opinion, but I think the only way to accomplish what you want is to have a bunch of people who know their max calibrated gripper close all squeeze the same dyno and see what they get. If it's different dynos and any given person's opinion, the info won't be worth much. I just don't think there is a useful way to make the comparison except what you've already done. Squeeze both and give an opinion.

What you say is true, I based all the info by only by my personal numbers. But maybe it can be a good way to make something going, more o less like you say, people test there stregnht and say wich gripper can close and wich can not, and make something like a conclusion.

But I think that is kind of hard since not everybody has a Dyno, but is kind of fun and interesting check different people and strenght and check wich gripper can close with certain grip strenght.