Hazmatt used for TSA PreCheck

In case anyone here has to fly just a little tip use you're DL # on your flights known traveler number. This only works if you have the Hazmat endorsement
I copied the blow section from there website.


TWIC® and HME holders can obtain TSA PreCheck expedited screening by entering the identification numbers printed on their TWIC® card or state-issued CDL during the airline reservation process. Active TWIC® card holders enter their TWIC® credential identification number (CIN) in the known traveler number (KTN) field of their airline reservation. The CIN is printed on the back of each TWIC® card in the lower left-hand corner. Active HME holders enter the two-letter state abbreviation and CDL identification number from their state-issued commercial driver’s license in the appropriate KTN field. (For example: NY12345678.)
Active TWIC® and HME holders can use their credentials to obtain TSA PreCheck™ | Transportation Security Administration

 

And a TWIC card will work also.