BS 131-7:1990 pdf free.Notched bar tests — Specification for verification ofthe test machine used for precision determination of Charpy V-notchimpact energies for metals.
BS 131-7 The horizontal reference surface X shall belevel in any two orthogonal directions to within 0°3′(1: 1 000) after installation. Whenshims have been used they shall be of ground hardened steel and should support the machine overat least 75 % of the contact surface.
Supports and anvils. Orientation of supports.The level of each testpiece support shall be checked individually andshall be parallel to the true horizontal referencesurface to within 0° 3′(1 : 1 000):
a) in a direction parallel to the plane of swing;b) in a direction perpendicular to the plane ofswing of the pendulum.The faces supporting the test pieces shall becoplanar to within 0.05 mm.
Recess.A relieving recess shall be provided inthe support faces at the junction of the anvil and testpiece support surfaces.The width of this recess parallel to the plane of swing shall not exceed 2 mm.
Orientation of the anvils.The face of each testpiece anvil shall be checked individually and shallbe parallel to the vertical reference surface Y towithin 0°3′ (1:1 000).
The anvil faces shall be coplanar to within 0.05 mm.5.5.4 Angle between test piece support and anvilfaces.The angle between the test piece support andanvil faces shall be 90土0° 6′ (see Figure 5).
Radius of curvature.The anvil tips, R, shallhave a radius of curvature of 1 ± 0.05 mm (see Figure 2).
Verticality.The anvil tips shall be perpendicular to the horizontal reference surface xin planes parallel to the Y reference surface and theintended plane of swing to within 0° 3(1: 1 000)(see Figure 3).
Taper of anvil.The angle of taper of each anvilshall be 79 ±1°.The distance between the anvil tips shall be 40 土0.05 mm measured at the position shownin Figure 2 and Figure 3.
Bearings and spindle.At the bearing position,the transverse play of the spindle shall not exceed 0.25 mm, and the radial play shall notexceed 0.03 mm.
The spindle axis shall be: a) parallel with respect to the horizontal reference surface X to within 0° 3′(1:1 000), andb) parallel with respect to the vertical referencesurface Y to within 0° 3(1 : 1 000).BS 131-7 pdf download.