Grade-8 Hex Flange Screws
These screws, which are made of premium alloy steel and heat treated to meet SAE Grade-8 mechanical standards, are dimensioned in accordance with IFI-111 regulations and include an added feature known as a recessed fillet radius, or “undercut”. They are available from Valley Fastener in all-inch standard lengths and diameters in coarse and fine thread with either plated and baked or phosphate and oil finished.
Before inserting a bolt, the holes do not need to be as exact or reamed out because burrs from punched or drilled holes do not interfere with the screw’s bearing surface.
A high clamp load ratio with low stress is provided by a homogeneous mating surface.
When combined with a hex flange nut, the higher clamp load is dispersed over a larger surface, improving joint integrity.