Fiber Optic Connectorization Epoxy


Fiber Optic Epoxies & Supplies

  • Long Pot Life Epoxies
  • High Class Transition temperature Epoxies
  • 5-Minute Epoxies

Thorlabs offers a wide range of epoxies for fiber optic pigtail connectorization. See the individual descriptions below for more details. We also offer general-purpose expoies and UV-curing adhesives.

Fiber Connector Epoxy

* Easy-to-Use 2g BIPAX
* 25-30 Connectors per Pack (Sold in Packages of 10)
* F112 and F120 Not Intended for Use with TECS Clad Fiber

F112 Long Pot Life, Room Temperature Cure
The F112 epoxy is an ideal epoxy for making room temperature terminations. The long 30 minute pot life allows more connectors to be produced from one mix. See the Specs tab for details.

F120 Fast Room Temperature Cure
The F120 epoxy provides a combination of fast cures and low shrinkage for high performance fiber optic connections. At room temperature, the connectors are ready for polishing within 1 hour; however, fully matured bonds require 4 to 6 hours. See theSpecs tab for details.

F123 Color-Keyed, High-Temperature Cure
This epoxy has a unique three-step color change formulation: unmixed components are light yellow, the mixed color is green, and after the required 100 °C high-temperature cure, the color is a deep reddish-amber.

Note: In general, we have found that using this product beyond its expiration date may result in increased curing times but does not significantly affect the performance if used within one year of the printed date.


High Temperature & Low CTE Epoxy

* Excellent Wicking for Fiber Optic Applications
* High Temperature Epoxy - Can Perform at Constant 200°C
* Passes NASA Low Outgassing Standard ASTM E595 with Proper Cure
* Color Changes Upon Curing From Amber to Dark Red
* 4 Hour Pot Life
* Pre-Measured, 4 g Packs

EPO-TEK 353ND is known industry wide as a high temperature epoxy. This two part, 100% solid, heat curing epoxy can be used in applications requiring constant performance at 200 °C. It can handle 300 °C to 400 °C for brief periods. The epoxy is vacuum compatible, passing NASA low outgassing standard ASTM E595. Thorlabs offers 353ND epoxy in pre-measured, 4-gram packs that provide repeatable performance and eliminate the need for measuring.

Please note that 353NDPK is classified as a dangerous good in some countries. Depending on the delivery location, this item may need to be shipped separate from the rest of your order at an additional charge. This 2-part epoxy is stocked within the USA and Germany. Ground shipment from these locations can ship via Fedex Ground at no additional charge. 


General Purpose 5-Minute Epoxy

* General Purpose, 2-Part Epoxy
* Easy-to-Use Dispenser Ensures Proper Mixing Ratio


Empty Epoxy Syringes


Empty Syringes For Epoxy Applications
Thorlabs offer 3 cc syringes in bags of 10, which are ideal for epoxy applications. Epoxies, such as our F112, come in a BIPAK with pre-measured amounts of the 2-part epoxy. After mixing the epxoy the contents of these packs can be emptied into a syringe for easy application.

We recommend our fiber optic disposal unit (FTDU, sold separately) to properly dispose of all syringes and epoxy.


Item #F112F120F123353NDPK**
Color, Cured Dark Blue Transparent, Straw Clear Reddish-Brown* Dark Red
Specific Gravity, Cured 1.200 1.220 1.200 1.18
Index of Refraction 1.51 n/a 1.56 1.5694 @ 589 nm
Viscosity, cPs, Mixed 1,800 14k Resin,
35k Hardener
4,000 3,000 - 5,000
Thixotropic Index 1.0 1.0 1.0 n/a
Operating Temperature Range -60 to 120 °C -60 to 115 °C -60 to 175 °C Cont:  -55 to 250 °C
Inter: -55 to 350 °C
Hardness, Shore D 86 72 87 85
Mix Ratio, pbw, Resin/Hardener 100/30 100/93 100/10 10:1
Glass Transition (Tg), Ultimate 102.00 °C n/a 120.00 °C ≥90 °C
Water Absorption 0.070% n/a n/a n/a
Coefficient of Expansion 6.20e01 ppm/°C 6.00e-05 cm/cm/°C >Tg: 2.03e02 ppm/°C >Tg: 54e-06 in/in/°C
Impact, Izod n/a 1.90 ft-lbs/inch of notch n/a n/a
Dielectric Strength n/a 400 V/mil 400 V/mil n/a
Dielectric Constant n/a 4.40 (1 KHz @ 25 °C) n/a 3.17 (1 KHz @ 23 °C)
Pot Life 2 g, 30 min 5 min 4 hr 3 - 4 hr
Working Life 2 g, 1 hr n/a n/a n/a
Cure Schedule 24 hr @ 25 °C or
1 hr @ 65 °C or
15 min @ 90 °C
24 hr @ 25 °C or
1 hr @ 65 °C
5 min @ 100 °C 30 min @ 80 °C
10 min @ 100 °C
5 min @ 120 °C
1 min @ 150 °C

*Unmixed color: clear light yellow. Mixed color: clear green/blue.
**Data is not guaranteed, only for reference. Different batches, conditions, and applications yield differing results.



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