公法線千分尺712公法線千分尺用于測量齒輪公法線長度，是一種通用的齒輪測量工具。編號測量范圍讀數值質量712-010-25mm0.01mm0.274712-0225-50mm0.356712-0350-75mm0.454712-0475-100mm0.600712-05100-125mm0.772712-06125-150mm0.961712-07150-175mm1.35712-08175-200mm1.62712-09200-225mm1.84712-10225-250mm2.03712-11250-275mm2.30712-12275-300mm2.68712-130-1in0.001in0.273712-141-2in0.355712-152-3in0.453712-163-4in0.599712-174-5in0.771712-185-6in0.960