Adhesion To Steel - refers to how strong the tape sticks (how hard it is to pull off surface), the spec literally means that if adhesion is 55 then it would take 55 ounces of pull per inch of tape width to break the bond between the tape and the stainless steel test panel when peeled back at a standardized rate and angle
Tensile Strength - the longitudinal strength of the tape which is not the same as tear (transverse) strength; it refers to a tapes ability to withstand force or stress or in other words how hard can you pull on the tape before it breaks apart
Thickness - a higher thickness tape usually equates to a higher performance/quality product
Elongation - measures how stretchable a tape is lengthwise - an elongation of 150% means the tape can be stretched over 1-1/2 times its original length before it breaks or stops stretching