Our high quality 400 mm drill bit is perfect for use with electric core drills for drilling on granite, hard stone, concrete, reinforced concrete, and other hard surfaces. Its durable construction will ensure smooth operation of the drills. We also provide bits of other sizes to meet different drilling needs. Segement Height: 7 mm. Threaded connection: 1 1/4. Dimond Core Drill Bits Bit Wet Dry Drilling Accessories Professional Tool 400 mm. Size: 26mm X 400/32 x 400/50 mm X 400/63 x 400/71 x 400/82 mm X 400/102 mm X 400/110 mm X 400/120 mm X 400/132 mm X 400/150 mm X 400/180 x 400 mm. All the items sent out from the UK Warehouse. All emails will be answered within 24 hours Sat. Please keep in mind that by no means we would ignore your emails and not respond on purpose.