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Universal high-pressure gasket material for industrial applications

KLINGERSIL® C-4408 is a universal high-pressure gasket material for industrial applications. This material has a low-carbon steel woven mesh insert that improves stress relaxation and makes this material suitable for fluctuating temperatures and pressures.

C-4408 has good resistance to oils, fuels, and hydrocarbons.

This material is manufactured with aramid fiber reinforced with a nitrile binder.
Klingersil C-4408


Typical Values Refer to 1/16" Thick Material Unless Noted

Creep relaxation ASTM F38B (1/32") 20 %
Compressibility ASTM F36J (1/32") 6 - 12 %
Recovery ASTM F36J 50 % minimum
KLINGER Hot Compression Test
Thickness Decrease 73°F (23°C)
Thickness Decrease 572°F (23°C)

12 % initial
22 % additional
Weight increase ASTM F146 after immersion in
Fuel B, 5h/73°F (23°C)

10 % maximum
Thickness Increase ASTM F146 after immersion in
ASTM Oil IRM 901, 5h/300°F (149°C)
ASTM Oil IRM 903, 5h/300°F (149°C)
ASTM Fuel A, 5h/73°F (23°C)
ASTM Fuel B, 5h/73°F (23°C)

0 - 5 %
0 - 5 %
0 - 5 %
0 - 5 %
Density ASTM F1315 119 lb/ft ³ (1.9 g/cc ³)
ASTM F104 Line Call Out F712112B3E11M6
Color Black


The pressure/temperature graphs shown are the most current method of determining the suitability of a gasket material in a known environment. However, chemical compatibility must also be considered.
pT diagram for thickness 1/16":
C-4408 Liquid
C-4408 Steam
In area 1 the gasket material is suitable using common installment practices subject to chemical compatibility

In area 2 appropriate measures are necessary for installation of the gasket to ensure maximum performance. Please call or refer to KLINGERexpert for assistance.

In area 3 do not install gaskets in these applications without first referring to KLINGERexpert or contacting KLINGER Thermoseal's technical support service.
The ability of a gasket to make and maintain a seal depends not only on the style and quality of the gasket material, but also on medium being sealed, the flange design, the amount of pressure applied to the gasket by the bolts and how the gasket is assembled onto the flanges and tightened. These factors are beyond the manufacturer's control. Please take note of our installation manual in TECHNICAL RESOURCES.