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20/02/2026

Non-Adhesive 2 to 1 Shrink Ratio
Art.-No. 309-20642 | TF21-6.4/3.2-PO-X-RD

Polyolefin heat shrink tubing resists most common oils, chemicals and fluids.

Heat Shrink Tubing 2:1

TF21 - available in a wide range of colours and sizes.

Quick and easy shrinking TF21 tubing is widely used for insulating, mechanical protection, strain relief, marking, and bundling.
The excellent balance of electrical, mechanical and chemical properties meet and exceed industrial standards.
TF21 is UL-224 listed and available in a wide range of sizes and colors.

Package size

60 m

75 m

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Heat shrinkable tubing 2:1 - flexible and coloured >

Base Data

Application	Due to it's versatility TF21 is suitable for a wide range of applications like electrical insulations, mechanical protection and marking.
Behaviour At Low Temperature	not cracking
Behaviour at Heat Shock	not refractive, not fluid, not dripping
Behaviour at low Temperature test method	SAE-AS23053
Brand Family	TF21
Color	Red (RD)
Elongation At Heat Aging	420%
Heat Aging Test	168h/175°C
Heat Aging test method	SAE-AS23053
Heat Shock Test	4h/250°C
PART DESCRIPTION	TF21-6.4/3.2-PO-X-RD
Packaging Type	reel
Part No.	309-20642
Product family	Insulation
Type	TF21-6.4/3.2

Product Dimensions


For Object Outside Diameter	3.84-5.76 mm
Longitudinal Change After Shrinkage	+/-5%
Printable	No
Recovered Diameter (metric)	3.2mm
Shrink Ratio	2:1
Size (imperial)	1/4"
Supplied Diameter (metric)	6.4mm
Volume Resistance	10¹⁴ Ω cm
Wall Thickness (metric)	0.64mm

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Material and Specifications

Dielectric Strength	30kV/mm
Elongation at break (min.)	400%
Elongation at break test method	ASTM D638
Flammability	UL 224 VW-1
Halogen Free	No
Material	PO-X
Material	Polyolefin, cross-linked (PO-X)
Min. Shrink Temperature	+220 °F (+105 °C)
Operating Temperature	-67°F to +275°F (-55°C to +135°C)
ROHS compliant	Yes
Test Method Tensile Strength	ASTM D638
UL File Number [Logo]	E143529 [RU]
UL Recognized (US and Canada)	No
UL Recognized (US)	Yes

Logistic and Packaging

Packaging 1 - Weight (kg)	1.4kg
Pkg. Qty.	75m

More Information

Calculators

Calculator tool for Heat Shrink Tubing

Calculator tool for Heat Shrink Tubing

for TF21-6.4/3.2 - Art.-No.: 309-20642
In selecting the right shrink tubing size it is important to consider to "80:20 rule". Shrink tubing should recover at least 20% and maximum 80% of its potential shrink range.
According to which specification would you like to check if the selected product is suitable for your application?

diameter

Please enter either the smallest and/or the largest outer diameter of the substrate.

Min mm Max mm

Cross-Section

Please enter either the smallest and/or largest cross-section of the object to be covered.

Min mm² Max mm²

perimeter

Please enter either the smallest and/or largest perimeter of the object to be covered.

Min mm Max mm
Wall thickness calculator

Wall thickness calculator

for TF21-6.4/3.2 - Art.-No.: 309-20642

Depending on the substrate dimensions when Heat shrink tubing is recovered the diameter and the wall thickness will change. This Calculator aims to offer a theoretical wall thickness for this situation.Please enter the outer diameter of the object to be covered

Outer diameter of object (A)

mm

Inner diameter of tubing after shrinking (B)

mm

Wall thickness fully recovered ( C )

mm

Solutions

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