mill heat treat, 7075T7351 mill heat treat, 7075T7351 dho (Mechanical) (OP) 30 May 14 11:09 7075T7351, the BOM says "mill heat treated". 1) what does that exactly mean? has to be heat treated to T7351 by Alcoa? 2) what is the benefit heat treated by mill? thanks. RE: mill heat treat, 7075T7351 berkshire (Aeronautics) 30 May 14 14:52 DHO, The spec you refer to is an alloy heat-treated, artificially aged, and cold worked to improve its strength and corrosion resistant properties. The mill as a general rule supplies the material at the T6 temper with the other tempers being done by the customer. If you can get the mill to do this for you, which they will with some sheets and plates, it will save you time and money if you do not have to do any forming on the part. here is a related thread thread330-336927: Clarification on difference between T73 and T7351/2 B.E. You are judged not by what you know, but by what you can do.