CHINA’S exports of rare earth magnets to the United States rose more than 20 percent in May from the previous month to their highest since at least 2017, data released by the General Administration of Customs showed Tuesday.

Rare earth magnets are widely used in medicine, consumer electronics and the military, although U.S. President Donald Trump in August last year signed a defense policy bill banning the purchase of rare earth magnets from China for the military in the 2019 fiscal year.

The most widely used types, prized for their strength, are those made with neodymium, one of the 17 rare earth elements.

Exports to the United States of permanent rare earth magnets, or material that will be turned into permanent magnets, came in at 430,961 kg, or around 431 tons last month, the customs data showed. That was up 21.5 percent from April and up 4.4 percent from May 2018.

It was also the highest monthly export figure on customs database records going back to January 2017.

In 2018, China’s exports of rare earth magnets to the United States were worth a total 1.325 billion yuan (US$192.7 million), the customs data showed.

Ryan Castilloux, managing director of U.S. consultancy Adamas Intelligence, said big fluctuations in the export numbers were normal. “I wouldn’t doubt that some of it is stockpiling but there’s nothing definitive there to point us in that direction,” he said.

Another key rare earth for the United States is lanthanum, which is used in the oil refining industry.

Exports of lanthanum oxide stood at 534 tons in May, the customs data showed. That was up 59.4 percent from April and up 14.1 percent year on year.

Exports of lanthanum carbonate, meanwhile, were at 400.1 tons, down 64.3 percent from April but more than double the 197 tons exported in May 2018.

China’s overall rare earth exports, which can fluctuate wildly, fell by 16 percent in May from the previous month, according to data released earlier in June.(SD-Agencies)