I just got my Iron Woody Super Gripper in the mail today. It does not come with any information on the grip poundages of the spring positions but there is a free program online with this information.

There are applications for IVANKO, Iron Woody & Hammar sports :

http://www.angelfire.com/ar/mathgod/sg/supergripper.html

I have four extra springs & have no idea how much force is the maximum but the software will chart it up to over 400 lbs with 3 springs. Even just two springs can achieve 250 lbs.

Hers a pic of me & my new super grippers…

I also got a set of five heavy grips about a month back & can nearly mash 250 lbs. But that last 7 mm seems to be the problem – the super gripper can be used to do partial reps on that final squeeze and I suspect the final squeeze of a wrist curl works the same muscles & tendons.

Finally I went to the hardware store and bought some thumb clamps to work my thumbs and fingers.

My goal is to close 400 lbs and I am doing additional forearm training such as hammer curls, reverse curls, pinches and weighted pull ups in addition to my regular training program.