Document ID: chunk:federal_register_of_legislation:F2015C00542:reg:1:p9
Version: federal_register_of_legislation:F2015C00542
Segment Type: reg
Provision Reference: reg 1 (pt 9/43)
Character Range: 169478–172334

value grade  Exposed area of the grid area
Gt2              between 5 and 15  per cent
Gt3              between 15 and 35  per cent
Gt4              between 35 and 65  per cent
Gt5              higher than 65  per cent

Annex 4
  Toughened-glass windscreens
1. Definition of type
 Toughened-glass windscreens shall be deemed to belong to different types if they differ in at least one of the following principal or secondary characteristics.
1.1. The principal characteristics are as follows:
1.1.1. The trade names or marks;
1.1.2. The shape and dimensions.
 Toughened-glass windscreens shall be considered as belonging to one or other of two groups for the purposes of fragmentation and mechanical-properties test, i.e.;
1.1.2.1. Flat windscreens, and
1.1.2.2. Curved windscreens.
1.1.3. The thickness category in  which the nominal thickness 'e' lies (a manufacturing tolerance of ±0.2 mm being allowed):
 Category I      e   4.5 mm
 Category II 4.5 mm < e   5.5 mm
 Category III 5.5 mm < e   6.5 mm
 Category IV 6.5 mm < e
1.2. The secondary characteristics are as follows:
1.2.1. Nature of the material (polished (plate) glass, float glass, sheet glass);
1.2.2. Colouring (colourless or tinted);
1.2.3. The incorporation or otherwise of conductors;
1.2.4. The incorporation or otherwise of opaque obscuration.
2. Fragmentation test
2.1. Indices of difficulty of the secondary characteristics
2.1.1. Only the nature of the material is involved.
2.1.2. Float glass and sheet glass are considered to have the same index of difficulty.
2.1.3. The fragmentation tests shall be repeated on transition from polished (plate) glass to float glass or sheet glass, and vice versa.
2.2. Number of test pieces
 Six test pieces from the smallest-developed-area series and six samples from the largest-developed-area series, selected as prescribed in Annex 13, shall be tested.
2.3. Different zones of glass
 A toughened-glass windscreen shall comprise two main zones, FI and FII. It may also comprise an intermediate zone, FIII. These zones are as defined below.
                     2.3.1. Zone FI:  Peripheral zone of fine fragmentation, at least 7 cm wide, all round the edge of the windscreen and including an outer strip 2 cm wide not subjected to assessment;
                     2.3.2. Zone FII:  Visibility zone of varying fragmentation, always including a rectangular part at least 20 cm high and 50 m long;
2.3.2.1. For vehicles of category M1, the centre of the rectangle shall be inside a circle having a radius of 10 cm centred on the projection of the middle of segment
V1-V2.
2.3.2.2. For vehicles of categories M and N other than M1, the centre of the rectangle shall be inside a circle having a radius of 10 cm centred on the projection of point 0;
2.3.2.3. For agricultural and forestry tractors and for construction-site vehicles, the position