ISO 7438-2020 pdf download.Metallic materials一Bend test.
6.3 Bending device with a V-block
The tapered surfaces olthe V-block shall form an angle of 180 – a (see Figure 2). The angle a is specified in the relevant standard.
The edges of the V-blodc shall have a radius between I and 10 times the thickness of the test piece and shall be olsuuuicwnt hardness,
6.4 Bending device with a damp
The device consists ala clamp and a former of u1liclent hardness. it may be equipped with a lever for applying force tot hr test piece (we Figure 3).
Because the position of the left lace of the clamp can influence the test results, the left face of the clamp (as shown in FIgure 3) should not reach up to or beyond the vertical line through the centre of the circular former shape.
7 Test piece
7.1 General
Round. square, rectangular or polygonal cross-section test pieces shall be used in the test. Any areas ol the matertal affected by shearing or flame cutttng and similar operations during the sampling of test pieces shall be removed. However, testing a test piece, the affected parts of which have not been removed, is acceptable, provided that the result is satisfactory.
7.2 Edges of rectangular test pieces
The edges of rectangular test pieces shall he rounded to a radius not exceeding the lollowing values:
— 3 mm. when the thickness of the test pieces is 50mm or greater’
— t,S mm, when the thickness of the test pieces Is less than 50 mm and more than or equal to 10 mm;
— I mmwhenthethicknessisiessthan 10mm.
The rounding shall be made so that no transverse burrs. scratches or marks are formed which can adversely affect the test results, However testing a test piece, the edges of’which have not been rounded. Is acceptable, provided that the result is satisfactory.ISO 7438 pdf download.