[tacitusarc]

It may be splitting hairs, but I think certain changes to hammers must qualify as invention, certainly, including the crosshatch innovation, the material science involved for both fiberglass and titanium handles, and the improved weight distribution. It's not clear to me what would be considered a complete reimagining of the hammer, as a hammer is such a broad category of tool. Is a mallet a hammer? When I smack something with the backside of an impact driver, is it a hammer? I sure use wrenches as hammers occasionally.

So, what's the line between inventing and refining?

[IgorPartola]

A slide hammer, a dead blow hammer, a flooring hammer, a nail gun, a staple gun, liquid nails/glue, screws and a screw driver (powered or not), a jackhammer, a power chisel.

If the idea behind a hammer is to use the momentum of a relatively large mass to drive a relatively small mass into a material, then the idea of a piece of steel on a handle is just the simplest thing you can manufacture as admittedly a versatile one but not necessarily the best one. If your task as the user is to join two materials together then hammer and nail won’t necessarily even look like hammer and nail (glue, screws). If the goal is to separate material like you might with a chisel, depending on the material you might not be using a manual hammer but something that looks very different, like a saw, a file, a jackhammer, etc.

What the person who mentioned the evolution of framing hammers is pointing out refinement of the hammer as it is. Creating a tool better suited to the user’s task is closer to what TFA is about.

[richardbrevig]

The marketing terms here are continuous innovation (that doesn't change user behavior) vs discontinuous innovation (that changes user behavior).