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close this bookCentring, Drilling and Counterboring / Countersinking - Course: Techniques for Machining of Material. Instruction Examples for Practical Vocational Training
View the document(introduction...)
View the documentPreface
View the documentInstruction example 3.1.: Shaft
View the documentInstruction example 3.2.: Die plate
View the documentInstruction example 3.3.: Adapter
View the documentInstruction example 3.4.: Draw-in bush


The present booklet contains 4 selected instruction examples which are intended to help practising and consolidating knowledge and skills acquired in the working techniques "centring, drilling, counterboring/countersinking".

In order to facilitate the preparation and execution of the work, the necessary materials, cutting and operating tools, measuring and testing tools and accessories are stated for each training example.

For the instruction examples 1 and 3 the steel is specified according to the value of its tensile strength in the unit "Megapascal" (MPa).

We also recommend knowledge required in addition to knowledge of centring, drilling, counterboring/countersinking which should be repeated before starting with the work. The specified sequence of operations gives the steps necessary for the production of the parts. This sequence of operations should be strictly observed if good quality is to be achieved, For each instruction example a working drawing is attached showing the required shapes and dimensions of the workpiece. The admissible deviations for sizes with no indication of tole-rances may be taken from the table below.

Nominal size

Admissible deviation in mm

0.5 - 6

± 0.1

6 - 30

± 0.2

30 - 120

± 0.3

120 - 315

± 0.5

The admissible surface roughness Rz is specified in µm (0.001 mm).