The Forrest Mjollnir was the first hammer with interchangable picks. Forrest designed this system in 1974. Forrest offered a nut pick, an alpine pick, a waterfall ice Sky pick, and atubular pick. These picks fit all versioins of the Mjollnir hammer but do NOT fit the Forrest Lifetime ice axes and hammers.
My Mjollnir has a curved hatchet-style handle, while my later Mjollnir IIIs have hammer-style handles.
↑ 132: Forrest Mjollnir
↑ 047: Forrest Mjollnir III
↑ 048: Forrest Mjollnir III
Nut hammers were for setting or cleaning nuts, testing fixed pitons, and driving the occasional pin but meant for lighter duty than a typical wall hammer.