https://www.commerce.gov/news/press-releases/2020/01/commerce-finds-dumping-imports-fabricated-structural-steel-canada-china

China has been skirting tariffs by dumping imports to the Canadian market. It's been going on for decades, but picked up in the past 4 years.

China sells cheap to Canada, the Canadian industry then sells at a cheaper rate to the US market.

https://www.commerce.gov/news/press-releases/2020/01/commerce-finds-dumping-imports-fabricated-structural-steel-canada-china

China has been skirting tariffs by dumping imports to the Canadian market. It's been going on for decades, but picked up in the past 4 years.