Thanks for doing this test, but I am honestly not too surprised at the result. I own and like much of the Channellock product line, but I happen to think Channellock v-jaw pliers are much better pliers for the same price.
The Griplock pliers have a very small arc engagement area compared to a regular pair of Channellocks, so any force on the hinge channel is going to be much more concentrated. The Channellock nutbuster pliers (which are really the correct plier for this brute force style task) have two separate and complete channels engaged at all times to keep the joint strong and stable which is a huge difference. What did surprise me a little bit is that the jaw teeth seem to be in better condition than I expected after tackling a grade 8 bolt. I expected them to be chewed up a bit more, but maybe that is just the slight blurriness of the pictures hiding the damage.
To all the Knipex fanboys. I own and use a lot of their products also and they have their pluses and minuses too, but you have to compare apples to apples here. The Griplocks are US made and they can be found very easily and locally for around $10 or in 2 packs with a larger 12" size for around $24. The only real competition for Griplock pliers at their price point is China made. They are good pliers for $10, but in my opinion the $12-14 Channellock v-jaws are much better bang for the buck. Knipex or NWS are better pliers in many ways, but they should be since they cost almost 3x as much. I personally only use my German push button style pliers in the garage, because they stick, grind, and jam too easily when working outside in dirt and mud. Channellocks can go anywhere with little or no fuss, and that's why I usually grab them first even though I have other options.
