Lalit Mohan Sharma, J.

1. The engineering unit of the petitioner-company is engaged in manufacturing nuts, bolts, M.S. rivets, etc., and claims that for the purpose of excise duty, mild steel rivets must be deemed to be covered by Tariff Item No. 26AA of the Central Excise Rules, 1944 , (sic) framed under the provisions of the Central Excises and Salt Act, 1944. According to the respondents the item is covered by Tariff Item No. 68.

2. If the item is held to be covered by Tariff Item No. 26AA (ia) the petitioner will be entitled to the exemption granted by Notification No. 75/67, dated 20th May, 1967, issued under Rule 8 of the Central Excise Rules, 1944 . The result of this writ application, therefore, is dependent on the decision as to which tariff item covers M.S. rivets.

3. The second column of Item No. 26AA(ia) of the Tariff which is said to be applicable according to the petitioner is in the following terms :

"Bars, rods, coils, wires, joists, girders, angles, other than slotted angles, channels other than slotted channels, tees, beams, zeds, trough piling, and all other rolled, forged or extruded shapes and sections, not otherwise specified."

The 68th item is the residuary item applicable, to all other goods not elsewhere specified (but excluding certain goods not relevant to the present case). If Item No. 26AA(ia) be held to cover the goods, Item No. 68 will automatically be not attracted.

4. Initially the petitioner filed a classification list showing rivets (as) falling under the Tariff Item No. 68, but on 5th April, 1978, the petitioner forwarded another classification list as evidenced by Annexures 1, l(a) and l(b) claiming that Tariff Item No. 26AA (ia) is applicable to M.S. rivets and on that basis the petitioner is entitled to exemption by virtue of Notification No. 75/67, dated 20th May, 1967, issued under Rule 8 of the Rules. This classification list was approved by the Assistant Collector, respondent No. 2, in exercise of the powers conferred under Rule 173B(1) and (2) of the Rules. According to the statement made in paragraph 4(d) of the writ application, petitioner, after Assistant Collectors approval, stopped collecting excise duty from the customers. Subsequently, the Assistant Collector, by his order on 18th April, 1979, as contained in Annexure 2, modified his earlier approval by substituting Tariff Item No. 68 instead of Tariff Item No. 26AA (ia). In the last column of Notification No. 75/67 the provision in regard to exemption of duty was stated. The petitioner has by the present writ application prayed for quashing Annexure 2 and the demand, Annexure 3, which followed it and for restoring orders in Annexures l(a) and l(b).

5. According to the case made out in the writ application, M.S. rivets are prepared to predetermined shape by a process of hot pressing known as forging out of duty paid iron rods and thus attract Item No. 26AA. By an application filed later in this case, the petitioner further asserted that the question whether M.S. rivets were covered under Tariff (Item) No. 68 or Tariff Item No. 26AA was raised throughout the country and as different States were not consistent in their stand, the matter was referred to the Central Board of Excise and Customs who after consideration issued an advice being Tariff Advice No. 37/82, dated 13th July, 1982, declaring that the disputed item was covered by Tariff Item No. 26AA(ia).

6. The petitioner has also taken a point of violation of principles of natural justice stating that the impugned Annexure 2 was passed without any opportunity to the petitioner to place his case before the authority concerned.

7. Mr. Ram Balak Mahto, the learned Counsel for the petitioner, contended that the process of manufacturing M.S. rivets is included in "forging" used in Item No. 26AA and the M.S. rivets, therefore, should have been exempted under the aforesaid mentioned notification. He relied on the definition of the technical terms "forging, extrusion and rol