Specifications

1. Offers a complete line of Metal Twist Drill Bits, such as straight shank, taper shank, etc;

2. Process: fully ground;

Dimensions

1. Drill diameter - The values indicated in the relevant dimensional standards apply in respect of the diameter of twist drills.

•Test point: On the lands at the corners

•Testing equipment: micrometer

2. Tapering of diameter - The diameter of twist drills usually reduces from the drill tip towards the shank in the area of the flutes.

•Test values: The taper on diameter amounts to 0.02 to 0.08mm over a length of 100mm.

•Test point: At the outside diameter on the land.

•Testing equipment: micrometer and indicating measuring instruments.

3. Parallel shank - Tolerance for shank diameter f11, Tolerance for roundness and parallelism 0.02mm for the shank length.

4. Length - The tolerance of length for the total length corresponds for the degree of accuracy "very coarse" according to DIN standards. The flute lengths given in the relevant dimensional stands are minimum dimensions.

5. Point angle

•Test value: σ=118°; σ=135°

•Test point: At the cutting edges

•Testing equipment: Universal bevel protractor indicating measuring instruments.

Materials and hardness

•Materials - M2, M35, M42, 9341, 4341, 4241, etc

•Hardness - HSS HRC63-66; HSSCo HRC64-68

•Test point: On outside diameter on the land or adjacent relieved land.

•Test equipment: Hardness Tester.

Marking

Twist drills with diameter 3mm and upwards shall be marked with:

1.Diameter;

2.Material: (HSS, HSSCo);

3.Additional and/or differing marking by agreement.