Direct tension indicating washer having enhanced emission of indicating material
View Patent ↗A direct tension indicating washer including 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; wherein the protuberance has four walls, each of the walls being substantially perpendicular to the first surface.
1. A direct tension indicating washer comprising:
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;
wherein the protuberance has four walls, each of the walls being substantially perpendicular to the first surface.
2. The direct tension indicating washer of claim 1 wherein:
the protuberance has a desired compression resistance, a volume of indicating material/desired compression resistance is greater than about 0.6×10 −6 cc per lb.
3. The direct tension indicating washer of claim 2 wherein:
the volume of indicating material/desired compression resistance is within a range of about 0.7×10 −6 cc per lb to about 0.9×10 −6 cc per lb.
4. The direct tension indicating washer of claim 1 wherein:
the indentation is longer than the protrusion as measured in a direction that is transverse to a line running radially from the centroid of the direct tension indicating washer.