Question on gst rates?

what is GST Rate on Plastic Articels ?

what is GST Rate on Plastic Articels ?

1) Nil - Plastic Bangles

2) 12% - Feeding Bottles

3) 18% - Primary polymers [all goods falling under 3901 to 3913] Ion exchangers based on primary polymers  (3914) Waste, parings and scrap, of plastics(3915) All goods including canes of plastics [3916] Tubes, pipes and hoses, and fittings therefor, of plastics [3917]  Self-adhesive plates, sheets, film, foil, etc. of plastics [3919] Other plates, sheets, film, foil, etc. of plastics [3920, 3921Articles for conveyance or packing of goods, etc. of plastics [3923]  Tableware, kitchenware, other household articles and Hygiene or toilet articles, of plastics [3924] Builder's wares of plastics, not elsewhere specified (like reservoirs, vats, shutters, containers, doors and windows and their frames, thresholds, blinds etc.) [3925]  PVC Belt Conveyor (3926 90 10) 

4) 28% - Floor coverings of Plastics, whether or not self-adhesive, in rolls or in form of tiles; wall or ceiling coverings of plastics [3918] Baths, shower baths, sinks, wash basins, bidets, lavatory pans, seats and covers, flushing cisterns and similar sanitary ware of plastics [3922] Other articles of plastics and articles of other materials of headings 3901 to 3914 [except bangles of plastic (3926 40 11) and PVC Belt Conveyor (3926 90 10)] [3926] 

1. We produce Dies for manufacturing all our castings.
2. This is done and required for all the different types of castings we manufacture.
3. Without Dies castings cannot be manufactured. Our dies are similar to Wooden/Aluminium/Metallic patterns used for Sand Castings shell molding as well as Aluminium Pressure Die Casting/Gravity Die Casting. (NATURAL BUNDLE)
4. Separate PO is issued to us by our customer Cost of these Dies and these are paid to us separately in free foreign exchange ( US $ or Euro or £) against our Invoices.
5. In most  cases the dies are  held in our custody till the part becomes obsolete or has lived its life.
6. This is not returned to to the Overseas customer unless asked for because orders for castings are repeated at regular intervals (Monthly/quarterly/six monthly/yearly or one in two or 3 years).
7. Many of these dies are made in our company by using inputs like Aluminium Blocks, Steel Blocks, etc.
8. Kindly help me in the matter to find Tax Rate on
   1. Castings
   2. Dies