Grade 8 Hex Cap Screws and Tap Bolts
Yellow Zinc Plated Grade 8 Steel Hex Head Bolts
A hex cap screw is a cap screw with a hexagonal head, designed to be
driven by a wrench (spanner). An ASME B18.2.1 compliant cap screw has
somewhat tighter tolerances than a hex bolt for the head height and the
shank length. The nature of the tolerance difference allows an ASME
B18.2.1 hex cap screw to always fit where a hex bolt is installed but a
hex bolt could be slightly too large to be used where a hex cap screw is
Hex Cap Screws, commonly referred to as Hex Bolts, or Hex Head Bolts are bolts with a shoulder in longer lengths. Hex Cap Screws are fully threaded in shorter lengths (usually around up to 1-1/2 inch, depending upon the bolt diameter), and partially threaded with a shoulder beneath the fastener hex head in longer lengths.
Grade 8 Yellow Zinc is heat treated and hardened, for a durable finished fastener. Grade C Yellow Zinc translates to Grade 8 or better. Grade 8 offers superior hardness to Grade 5, because the fastener is thru hardened to maximize the density of the metal.