The Differences Between 3/4 and 1/4 Heat Shrink Tubing Roll
Heat shrink tubing is a type of thermoplastic tubing that can shrink when heated. It is made of high polymer and has heat shrink properties. It will shrink along the radial direction when heated, hence it is called heat shrink tubing. Once it shrinks down it stays shrunk down, and then it can more permanently seal whatever it is covering.
How to select the right heat shrink tubing?
Before you use it you need to get the right heat shrink tubing. Here are some important parameters:
The diameter size of the heat shrink tubing must be larger than the diameter of the underlying materials to be covered. It is recommended that the heat shrink tubing should shrink by at least 20% and not more than 80% of its normal diameter. So select the tubing that is approximately 20-30% larger than the measurement.
The shrink ratio of the heat shrink tubing is the relationship between the original size of the tubing and its shrunken form following application. It indicates the rate that the tubing shrinks to.
3:1 shrink ratio heat shrink tubing : This shrink tubing will be one-third of its original size once the heat is applied. The diameter of a tubing, 24 mm, will recover to 8 mm — 67% shrinkage.
4:1 shrink ratio heat shrink tubing : This shrink tubing will be one-fourth of its original size once the heat is applied. The original heat shrink tubing is four times than Its shrunken form. The diameter of a tubing, 101.6 mm (4”) will recover to 25.4 mm (1”) — 25% shrinkage.
Therefore, make sure the heat shrink tubing would tightly cover the underlying material to be covered.
3. Wall thickness
There are three wall thicknesses of heat shrink tubing: thin-wall, medium-wall and heavy-wall.
Thin-wall heat shrink tubing has a wall thickness ranging from 0.4 to 0.82 millimeters after shrinking. It is often used for low voltage applications.
Medium-wall heat shrink tubing has a wall thickness ranging from 1.6 to 3 millimeters after shrinking.
Heavy-wall heat shrink tubing has a wall thickness ranging from 3.2 to 4.7 millimeters after shrinking. It offers excellent mechanical protection against and offers strong impact resistance.
4. Common materials
Polyolefin heat shrink tubing : the most popular material
Adhesive-lined Polyolefin: more secure
PVC: more cheaper
There are two shapes for heat shrink tubing: round and flat.
The tubing with a diameter up to 6.4 mm is always round to make use easier.
The tubing with a diameter ranging from 6.4 to 16 mm is available both round and flat.
The tubing with a diameter of 16mm or higher is always flat.
At last please pay attention to longitudinal shrinking. Heat shrink tubing shrinks in length when the heat is applied. This longitudinal change after shrinking is indicated in a percentage.
How long do you need to cut? Heat shrink tubing will shrink around 5-15% of the original length. So cut the tubing longer than the length you actually want.
What are the differences of them? Maybe they are all the same except shapes and diameters according to ‘How to select the right heat shrink tubing?’ (from 1 to 6).
Shapes: The shape of 3/4’’ heat shrink tubing roll is always flat. The shape of 1/4’’ heat shrink tubing roll is usually round, but sometime flat.
Diameter: It is said that the supplied inner diameter of the heat shrink tubing and the size of the underlying materials to be protected should not exceed a 40% ratio to allow for effective coverage. It means that the size of the underlying to be covered is different. Hence select the right heat shrink tubing roll for your requirements.