... diameter 19.75mm 5. Weldon shank Zhejiang Xinxing Tools Co.,Ltd (CHTOOLS)We are professional manufacture of cutting ... us.Core Drill1. Weldon shank, with more stable clamping for stable cutting and finish of holes.2. Additional one ... such as steel structure project, railway traffic, bridging, shipbuilding, machine manufacture, aviation and spaceflight. drilling machine for Cutting tools HSS core drill