Question

1. What does ST , PT and SC stand for.
2. What is the mark on A325 type 3 head that is not on the A325 type 1?
3. What is the nut rotation from the snug-tight condition for each bolt for turn-of –nut pre- tensioning in amount of turn and degrees required, both faces normal to bolt axis:3/4in A325 2.75 in. length,3/4in A490 2.75in length,7/8in A490 4in length and 7/8in A325 8in length.

Answer 1

Answer 1)

PT stands for Partial Thread

SC stands for Slip Critical Connection

ST stands for Steel

Answer 2)

Below is the difference between head markings of Type1 and Type 3 A325 bolts.

Answer 3)

Refer below table for solution.