Method of test||||
Definition of Vickers
A diamond indenter, in the form of a right pyramid with a square base and an angle of 136° between opposite faces, is forced into the material under a load F. The two diagonals, d1 and d2 of the identation left in the surface of the marerial after removal of the load are measured and their arithmetic mean d calculated. The area of the sloping surface of the indentation is calculated, the indentation being considered as a right pyramid with a square base of diagonal d and a vertex angle of 136°.
The Vickers hardness is the quotient obtained by dividing the load F, expressed in kilogrammes-force, by the sloping area of the indentation expressed in square millimetres.
SYMBOLS The symbols used are as follows: F = Load in kilogrammes-force (kgf). d = Arithmetic mean of the two diagonals, d' and d", in millimetres (mm). HV = Vickers hardness.
Proven accuracy, even when testing the most awkwarly shaped parts of inaccessible places, irrespective of size or dimensions! These are the unique features of the Penetrascope®, the Hardness Tester specially designed to enable tests to be made in situ whether on the laboratory bench, factory floor, or in the field.
No longer is it necessary to destroy your specimen in order to test it.
Using the 136° Diamond Pyramid inentation principle, well known for its accuracy and dependability, the Penetrascope® has been tested by the National Physical Laboratory and other well known Institutions and is guaranteed accurate within the limits of British Standards BS: 427, BS: 860 and ISO recommendations R81 - R192 - R399 - R409.
The consistent accuracy of the Penetrascope® and its ability to reproduce its results have been proved by hundreds of well-known Works, both in Europe and overseas.
Although suitable for tests which could not be made with any other hardness testing machine, the Penetrascope® is readily transportable and may be used to test a wide variety of materials ranging from thin metal strip to heavy components or assemblies weighing several tons.
The many interchangeable clamps make the Penetrascope® the most versatile hardness tester available, either for production or special testing. Conversion tables giving the equivalent Rockwell and Brinell Hardness Scale Readings are supplied with each instrument.
The Penetrascope® is provided with a precision ground 136° pyramidal diamond indenter. Instantly variable loads of up to 50 kgf are applied by means of a handwheel operating a highly efficient hydraulic thrust unit calibrated with deadweights. The large, easy to read, Load recording Dial ensures absolute accuracy and can be zeroed to maintain accuracy under the most extreme climatic conditions.
The indentation is viewed through a built-in microscope having a magnification of 180X and is measured with enclosed, movable, knife-edged shutters to an accuracy of one micron ( .001 mm ). The light load applied provides a non-destructive method of hardness testing with the minimum marring of the surface under test.
The Standard Penetrascope® (weighing only 9 kg ), shown above, is finishe in a durable Polychrome and supplied with a Carrying Case for easy transportation.