Direct tension indicating apparatus
A direct tension indicating washer apparatus includes a direct tension indicating washer; a base washer; and an anti-rotation feature to prevent rotation of the direct tension indicating washer relative to the base washer.
1. A direct tension indicating washer apparatus comprising:
a planar direct tension indicating washer;
a planar base washer; and
an anti-rotation feature to prevent rotation of the direct tension indicating washer relative to the base washer;
wherein the direct tension indicating washer comprises:
a first surface having a protuberance formed thereon;
a second surface having an indentation formed opposite the protuberance;
an indicating material positioned in the indentation; and
a channel leading from the indentation to an outer diameter of the direct tension indicating washer.
2. A direct tension indicating washer apparatus comprising:
a planar direct tension indicating washer;
a planar base washer; and
an anti-rotation feature to prevent rotation of the direct tension indicating washer relative to the base washer.
3. The direct tension indicating washer apparatus of claim 2 , wherein:
the anti-rotation feature comprises a tab on one of the direct tension indicating washer and the base washer and a notch on the other of the direct tension indicating washer and the base washer, the tab received in the notch to prevent rotation of the direct tension indicating washer relative to the base washer.
4. The direct tension indicating washer apparatus of claim 2 , wherein:
the anti-rotation feature comprises two tabs on one of the direct tension indicating washer and the base washer and two notches on the other of the direct tension indicating washer and the base washer, the tabs received in the notches to prevent rotation of the direct tension indicating washer relative to the base washer.
5. The direct tension indicating washer apparatus of claim 2 , wherein:
the anti-rotation feature comprises a pin on one of the direct tension indicating washer and the base washer and an opening on the other of the direct tension indicating washer and the base washer, the pin received in the opening to prevent rotation of the direct tension indicating washer relative to the base washer.
6. The direct tension indicating washer apparatus of claim 2 , wherein:
the anti-rotation feature comprises two pins on one of the direct tension indicating washer and the base washer and two openings on the other of the direct tension indicating washer and the base washer, the pins received in the openings to prevent rotation of the direct tension indicating washer relative to the base washer.
7. The direct tension indicating washer apparatus of claim 2 , wherein:
the base washer is a second direct tension indicating washer.
8. The direct tension indicating washer apparatus of claim 7 , wherein:
the second direct tension indicating washer comprises:
a first surface having a protuberance formed thereon;
a second surface having an indentation formed opposite the protuberance;
an indicating material positioned in the indentation; and
a channel leading from the indentation to an outer diameter of the direct tension indicating washer.
9. The direct tension indicating washer apparatus of claim 8 , wherein:
the second surface of the direct tension indicating washer is positioned adjacent to and facing the second surface of the second direct tension indicating washer.
10. The direct tension indicating washer apparatus of claim 8 , wherein:
the indentation of the direct tension indicating washer is aligned with the indentation of the second direct tension indicating washer.
11. The direct tension indicating washer apparatus of claim 8 , wherein:
the direct tension indicating washer is calibrated for a first bolt tension and the second direct tension indicating washer is calibrated for a second bolt tension.
12. The direct tension indicating washer apparatus of claim 11 , wherein:
the first bolt tension is different than the second bolt tension.