Good memory there Savar for being without your books. I do have mine however.
In D6 Adventures it gives the following examples for object toughness
Object Construction Toughness
Flimsy (plywood door) 1D
Tough (hard wooden door, most guns) 2D
Sturdy (bolted steel door, personal safe) 3D
Very sturdy (a few layers of steel) 4D
Reinforced (numerous layers of steel) 6D
If the attempt is successful, compare the skill total with
the object’s damage resistance total (its Toughness modified by size,
thickness, flaws, supports, etc.). Items that take at least 13 points above
their damage resistance total are severely damaged, if not destroyed.
Items taking less than that are weakened, and another attempt may be
made (with the object having a reduced damage resistance total and
possibly other problems).
Toughness is an ojects Physique.
Body Points: If your gamemaster is using this characteristic, roll your
character’s Physique and add 20 to the total.