Ninomiya Electric Wire Ninomiya Electric Wire Co.,Ltd.60th Anniversary

HRWHeat-Resistant Wires

Ceramic-yarn Sleeve: CERAC-SL

Compliant with RoHS2
Normal usage temperature:1000℃
Upper usage temperature limit:1200℃

The ceramic-yarn sleeve, CERAC-SL, is an ultrahigh-temperature-resistant sleeve that is made of cylindrically braided ultrahigh-temperature-resistant alumina filament fiber. CERAC-SL shows flexibility at high temperature nearly equal to that at normal temperature. Also, it maintains satisfactory tensile strength even at high temperature. It hardly shrinks or absorbs moisture. Its normal usage temperature is 1000℃ with an upper usage temperature limit of 1200℃. It is ideally used in applications such as the following: insulating or protecting thermocouples and heaters; insulating wire around furnaces; and protecting hoses, tubes, and electric wire from sparks in ironworks, aluminum refineries, etc.

Features of CERAC-SL

  • -Maintains strength and flexibility even after it is heated
    CERAC-SL maintains flexibility at temperatures of 1000℃ or more nearly equal to that at normal temperature. Even at a temperature of 1200℃, the tensile strength of CERAC-SL is 1.5 to 2.0 times as strong as that of conventional silica fiber.
  • CERAC-SL is not RCF (Refractory Ceramic Fiber).
    It has different chemical components and a manufacturing method from those of refractory ceramic fibers, that are listed as a toxic substance under the Japanese Industrial Safety and Health Act.
  • -Hardly absorbs moisture
    CERAC-SL hardly increases in weight, even after exposure for 24 hours in an environment where the temperature is 20℃ and the humidity is 100%. Therefore, it hardly absorbs moisture.
  • -Contains no acid and chlorides
    Since CERAC-SL contains no acid or chlorides, it is chemically stable. Even if it is placed in a highly humid environment in which the humidity is nearly 100%, it does not affect heat elements or other metals; however, it reacts with molten copper and molten tin exceptionally.


Part No. Inside diameter X Outside diameter Estimated weight
Estimated size (mm) g/m
CERAC-SL  1.6 1.6 x 3.2 8.5
CERAC-SL  3.0 3.0 x 4.6 13.0
CERAC-SL  5.0 5.0 x 6.6 15.6
CERAC-SL  6.0 6.0 x 7.6 19.9
CERAC-SL  7.0 7.0 x 8.6 24.3
CERAC-SL  10 10.0 x 11.6 30.9
CERAC-SL  13 13.0 x 14.6 34.0
CERAC-SL  16 16.0 x 17.6 46.9
CERAC-SL  20 20.0 x 21.6 52.1
CERAC-SL  25 25.0 x 26.6 79.5
CERAC-SL  32 32.0 x 33.6 87.5
CERAC-SL  38 38.0 x 39.6 143.0


Transparent (white)
Formation Continuous fiber
Normal usage temperature 1000
Upper usage temperature limit 1200
Specific gravity 2.8
Tensile strength kgf/mm2 130
Elastic modulus kgf/mm2 6000
Fiber diameter μm 7
Chemical ingredients Al2O3  60
SiO2   40

0.8 mm sewing thread

This is the same long-fiber aluminum thread as the ceramic fiber sleeve.
Tying the end of the ceramic fiber yarn sleeve will help keep the wires together.
(This is an optional product)


CERAC-SL is as flexible as braid.

Example of use

A heat-resistant electric wire is coated with CERAC-SL to protect the insulation of the wire.