鋁製戒指心軸 1-16（美國尺寸）

I’ve used this mandrel to size rings for a few weeks now, and the calibration is spot on—every ring I measure matches the same size on my set of old tools. The aluminum surface feels smooth and sturdy, and the markings are etched deep enough that they won’t wear off with regular use.

I’ve used cheaper mandrels before and always second-guessed the sizing, but this one gives me the same result every single time—the calibration is spot on. Even after dozens of rings, the marks haven’t worn or faded at all.

Finally, a mandrel that actually gives me consistent sizing across multiple rings. The precision calibration is perfect for my production work.