Cir. No.13/13/1994-CX, dt. 03/02/1994
- Document type
- Circular
- Reference no.
- A
- Dated
Laminated safety glass - Measurement of thickness
Subject : Central Excise - Determination of thickness of Laminated Safety Glass
Laminated Safety Glass falling heading No. 7004.20 is chargeable to concessional rate of duty @ Rs. 31.50 per mm. thickness or part thereof per Sq. mt. in terms of S.No. 4 of Notification No. 68/87 dated 1.3.87 as amended.
2. Representations have been received that different practices have been adopted for determination of thickness of laminated safety glass. It has been represented that the Board had issued a Circular No. 3/85 dated 22nd January, 1985 relating to determination of thickness of sheet glass. In this circular it was clarified that the method for determination of thickness of sheet glass as prescribed in ISI (IS:2835 - 1977) should be applied. The present request is that in the case of laminated safety glass the method for determination of thickness should also be as prescribed in ISI. The board has accepted the request and the method for determination of thickness of laminated safety glass as mentioned in ISI is given below for application.
3. In ISI (IS:2553 - Part I 1990, Para 5.12, it has been mentioned that the thickness of safety glass shall be measured in accordance with the method prescribed in para 5.1 and Annex. B of IS:2835 - 1987 which is given below:-
Apparatus - Screw Calipers - with an accuracy of 0.01 mm.
Marking of points - Divide the rectangular sheet into 4 equal segments as shown in Fig. Measure the thickness of the glass sheet using screw calipers at all the four points 1,2,3 and 4 as show in Fig. The individual thickness at patch of the four points shall be within the range of nominal thickness.
4. In terms of para 5.3.1 of IS:2553 Part I:1990 laminated safety glass shall be of thickness as specified in the Table:
| S.No. | Nominal | Range of | Dimensional Tolerance |
| Thickness (mm) | Thickness (mm) | on cut size (L&W) (mm) | |
| 1. | 3.5 | 3.1 to 3.7 | 2.5 |
| 2. | 4.0 | 4.0 to 4.8 | 2.5 |
| 3. | 5.0 | 5.0 to 5.8 | 2.5 |
| 4. | 6.0 | 6.0 t0 6.8 | 2.5 |
| 5. | 8.0 | 8.0 to 8.8 | 3.0 |
| 6. | 10.0 | 9.8 to 11.0 | 3.5 |
From the above table it is clear that if the range of thickness of glass is between 6 mm to 6.8 mm then the nominal thickness should be 6 mm.
5. In terms of para 5.3.1.1 of IS:2553 Part I:1990 if agreed between the purchaser and the supplier, nominal thickness of safety glass, other than those specified in Table may also be supplied. In such cases the range of thickness shall be those which are applicable to immediately lower thickness, as specified in Table.
6. The above method is also applicable to Toughened Safety Glass. For further details ISI (IS:2553 Part I :1990) literature may be referred to. Disputes relating to determination of thickness of laminated safety glass, if any, may be decided accordingly.
Sd/-
(Arvind Singh)
Deputy Secretary to the Govt. of India