Antidumping and countervailing duties (AD/CVD) are not tariffs and are not in the Tariff Schedule. Although the ITC has a role in AD or CVD investigations, the rates of duty are set by the International Trade Administration (ITA) of the Department of Commerce.
CBP maintains a public database of many (but not all) instructions implementing the orders at:
The two sites linked below can be used to find the Department of Commerce case number, which can be used when searching the CBP instruction site linked above.
A list of AD/CVD orders that were in effect on the date of update can be found at here.
For recent or ongoing investigations see: