Thermal conductivity; the time rate of heat flow through a unit area of a homogeneous material in a direction perpendicular to isothermal planes induced by a unit temperature gradient. In English (inch-pound) units of measurement, it is the number of BTUS that pass through a 1 inch (25 mm) thickness of a 1 square foot (0.09 m2) sample of material in 1 hour with a temperature difference between the two surfaces of 1° F. It is expressed as Btu·inch/h·ft2·°F.
K
Kerf
(1) a slit or notch made by a saw or cutting torch; (2) the width of cut made by a saw or cutting torch.
Kesternich Test
Simulates acid rain conditions by subjecting test specimens to a sulfur dioxide atmosphere as well as condensing moisture for the purpose of evaluating rust/corrosion characteristics.
Knee Cap
A metal cover trim that fits over a panel rib after it has been cut and bent.
Knee Joints
See Knuckle
Knuckle
A metal closure, either shop-or pre-fabricated, installed over the cut seam of a continuous metal roof panel at the transition from a steep-slope roof to a vertical roof or wall.