Heatshrink Tubing 101 - Measuring, Minimum/Maximum Supplied/Recovered Diameters
Heatshrink is a circle. To measure the diameter - the length of a straight line passing through the center of a circle is the correct way to measure (see image below).
The two most misunderstood specifications of heatshrink tubing
Minimum Supplied Diameter
The Minimum Supplied Diameter is the minimum diameter of the tubing before shrinking. Minimum is the KEYWORD.
A 3/8” shrink tubing will have a minimum of a 3/8” inner diameter. It can be more, but not less.
Maximum Recovery Diameter
The Maximum Recovery Diameter is the maximum diameter that the tubing will be, after it is shrunk down. It can shrink down to a smaller inner diameter, but it is specified to shrink down to AT LEAST the Maximum Recovery Diameter.
I hope Heatshrink Tubing 101 helps you pick the right product for your application!