hyphenation - Hyphenating measurements in case of a fraction

I am now quite comfortable with the rules of hyphenating measurements (For example, 5-foot-long rod, 7-inch-long handle, etc.) However, what is the rule for hyphenation if the number is a fraction. Say, 1/2-inch-long piece of ginger? I would ideally want to keep the fraction, the instance I am using it in, does not allow the usage of "half-inch-long".