Nah man, your mistaken. The 125 str is hardcapped. Enhancing with DC would only increase the Durability had it been lower, but its powderable anyway.. It had 70Energy/30Phys before. Copper was the best ingot for the job. =p
(Tested facts: DC/spined will not lower 125Str HardCap items)
edit: (and gold ingots also lower Str req, but not on 125str hardcap items)