Features Micrometer lead screw rod provides 0.0001 inch direct reading accuracy and it is easy to adjust. Double bar holder allows greater boring range without extreme deviation, practical. 1 DIV = 0.001 inch Ø → ║ ← 0.001inch Ø, which means that on the 0-50 dial, when the dial is rotated by 1 division / scale, the stroke radius movement of the boring head is 0.001 inch and the diameter movement is 0.002 inch. When the direction of the dial is reversed, the clearance between the gear trains is listed below. Via craft by many experts, such a boring head set is entitled with high performance according to strict rule. Feature: 1. Micrometer lead screw rod provides 0.0001 inch direct reading accuracy and it is easy to adjust. 2. Double bar holder allows greater boring range without extreme deviation, practical. 3. 1 DIV = 0.001 inch Ø → ║ ← 0.001inch Ø, which means that on the 0-50 dial, when the dial is rotated by 1 division / scale, the stroke radius movement of the boring head is 0.001 inch and the diameter movement is 0.002 inch. 4. When the direction of the dial is reversed, the clearance between the gear trains is listed below. 5. Via craft by many experts, such a boring head set is entitled with high performance according to strict rule. Specification: Item Type: Boring cutter 2 inch countersunk head with R8 handle Head Circumference: 2 inch Boring Hole: 1/2 inch Cross Hole Diameter: 1/2 inch Maximum Offset: 5/8 inch Thread: 1.5 inch-18inch Graduation Rate: 0.001 / 0-50 Package List: 1 x Boring Cutter and Boring Tool Holder 9 x Drill Bit 3 x Hex Wrench 1 x Storage Box Package List 1 x Boring Cutter and Boring Tool Holder 9 x Drill Bit 3 x Hex Wrench 1 x Storage Box