ISO 2739-2012 pdf free download

ISO 2739-2012 pdf free download.Sintered metal bushings Determination of radial crushing strength
Bagues en metal fritté — Determination de Ia résistance a I ‘écrasement radial.
This ISO 2739 specifies a method of measuring the radial crushing strength of sintered metal parts in the form of hollow cylinders, commonly known as bushings.
This method is applicable to sintered bushings composed of pure or alloyed metal powders.
2 Principle
A hollow cylinder is submitted to a continuously increasing radial load until breakage occurs, provided that the deformation does not exceed 10 % of the diameter, The maximum load observed is used to calculate a value in relation to the dimensions of the hollow cylinder known as ‘radial crushing strength”.
3 Apparatus
3.1 Pressing apparatus, that enables a radial load to be applied to a hollow cylinder.
3.2 Load-measurIng device, accurate and readable to 0,1 % of the full scale. The lowest testing range that
can provide a measureable result should be used.
3.3 Loading plates, two flat, ground, hardened steel plates of sufficient size to encompass the test specimen
that can be fastened to the press platens and that will remain parallel.
4 Test piece
The test piece (see Figure 1) shall be in the form of a sintered hollow cylinder (which may or may not be oilimpregnated). without flanges. notches, grooves, pronounced chamfers, drilled holes, oilways or keyways. If necessary, the cylinder may be machined but, in this case, the results obtained may differ from those obtained with a cylinder that has not been machined.
5 Procedure
5.1 Clean any surface oil from the specimen and measure the outside diameter, the inside diameter and the length within 0,5 % tolerance.
For test specimens with an outside diameter < 10 mm, the outside diameter may be measured to the nearest 0,05 mm.
For test specimens with an inside diameter < 10 mm. the inside diameter may also be measured to the nearest 0.05 mm.
For test specimens with a length ranging from  2 mm to < 10 mm, the length may be measured to the nearest 0,05 mm.
For test specimens with a length < 2 mm, the length may be measured to the nearest 0,01 mm,
5.2 Wipe the loading plates clean and lay the test specimen in the central region of the lower plate. the axis of the test specimen being parallel to the planes of the plates (see Figure 2).
5.3 Bring the upper plate and the test specimen into contact and slowly apply the diametric load at a rate (platen speed) that does not exceed 5 mmlmin.
5.4 Record the load at which the test specimen fractures or the first reading at which the applied load drops. The measuring value of the load should be kept at 0,1 % of the total load.ISO 2739-2012 pdf free download.