Originally Posted by
79pmooney
I look at those hubs and those removers and simply think that's collectively poor design to have one of the most highly torqued tool used on a bike to have that little material at the key spot. And yes, a delicate balancing act between hardness and strength with the real answer being more material.
Other, thicker-wall tools were available for the Atom/Regina/Zeus splined interface, but those often required removing axle locknuts to seat the tool. In the case of Phil hubs, this wasn't possible, which is why they produced their extra-thin remover tool. That tool became popular with other hubs as well, since there was no need to remove the locknuts to seat the tool.
Both Park and Shimano make good tools. But designing (or not designing and simple following along and making) FWs and hubs that require that thin a tool - well we really need a new metal that is substantially stronger and brittle failure free than steel. Or live our lives dedicated to the notion that FW threads will always be properly greased and not sit for years and decades, then removed. Or just accept that every once in a while, those tools break. (A good reason to clamp them in a vise and turn the wheel with both hands vs using a big wrench. Much less exciting. You don't slam your hands into things.)
As others have noted above, the Shimano tools were impact-rated, but they can still fail. Fortunately, the need for unbreakable freewheel tools has been largely obviated by the wide adoption of freehubs, whose cassette lockrings don't need to be super-tight, and don't self-tighten with use. Only those of us who use and service the older technology need suffer with the breakable remover tools.