Music Wire Compression Spring, Steel, Inch, 0.72" OD, 0.085" Wire Size, 2.404" Compressed Length, 4" Free Length, 33.59 lbs Load Capacity, 21 lbs/in Spring Rate (Pack of 10) Highly magnetic steel music wire for greater strength than stainless steel or copper wire Spring ends are closed and ground flat (squared) for efficient force transfer and reduced possibility of tangling Load capacity of 33.59 pounds Maximum operating temperature of 250 degrees F (121 degrees C) Dry to the touch oil finish for added corrosion resistance