The raw materials of the lifting chain are steel, and customers often purchase several tons and several tons. The lifting chain is often raised because of the price of steel. Because the raw material of the chain is round steel. The price of raw materials will of course affect the price of the chain. Therefore, the quotation of the chain is generally in the short term. The offer may not be applicable a month ago. Sometimes even the offer today, it will not be applicable in three days. Some customers with large demand often hoard some chain backup, which can reduce some costs. Then there is the decrease in the output of round steel, and the price will be raised. The chain is not to other products, and the cost is relatively stable. A client on my side set up a batch of chains in June, for various reasons for delivery in early December. If his batch of chains are calculated at the price in December, the price varies more than 10,000 yuan. Making products must be calculated based on cost, so the price of raw materials directly affects the price.