Seals for Aircraft and Defence Industry

Polyseal is a proven manufacturer of sealing elements in the aerocraft and defense industry and can provide optimal sealing for many applications. The materials and products suggested in this review can be mounted on anything from light to heavy land weapons to military aircraft.
Our sealing products are used in a wide range of systems including flight control, landing gear, brakes, engines, fuel control …


Polyseal engineering expertise, material development, product range and service capabilities confirm its position as a well-known manufacturer of sealing products in the aircraft and defense industry market.



Polyseal products are used in military aerospace and other defense industry projects and are reliable sealing solutions in a wide range of critical applications such as:

  • Landing gear systems
  • Flight control and management
  • Braking systems
  • Hydraulic user systems


Our commitment to solving technically sophisticated applications is supported by our industry-leading portfolio of elastomeric, thermoplastic and thermoplastic composite materials. Extremely high and extremely low temperatures, chemical influences and fuel impermeability are just some of the characteristics of these applications.


Polyseal products are used in transport and fueling equipment in aircraft fuel systems:

Parts in contact with jet fuel

Orao Jet engine


Working with the defense sector, we have learned that precision, reliability and efficiency must be imperative in our work. Long-term cooperation and dedication to this work has produced the necessary knowledge and offered sealing solutions for the most technically sophisticated applications.



  • Hydraulic installations
  • Actuators
  • Shock absorbers
  • Hydraulic pumps and motors
  • Pneumatic installations
  • Braking systems
  • Driving systems
  • Systems and testing equipment
Land military equipment 21


Composite seals and bearings in the most demanding applications require different materials with specific properties, as well as their combinations. We ensure that all materials such as rubber, PTFE and other high performance materials meet the demanding specifications and are approved by users in the aerospace and defense industries.

The extremely diverse and demanding applications in aerospace and defense equipment also require an extremely wide range of speeds, operating temperatures, chemical and environmental impacts, reliability in use and long life. 

Here we will describe some properties of rubber and PTFE materials that are recommended for use in these applications. Other materials are available. For more details contact us…



Linear speed:
  • Elastomeric materials, Rubber ≤ 3 m/s
  • PTFE materials ≤ 15 m/s

Recommended values may differ depending on seal design and operating conditions.

Chemical compatibility
  • Elastomeric materials, sensitive to the action of oils and lubricants. Chemical reactions between specific additives in the environment affect the physical properties and lead to seal damage.
  • PTFE materials are compatible in almost all media and all conditions.
Temperature range of use Recommended elastomeric materials, rubber:

  • Rubber (NBR) od -54°C do +135°C,
  • Fluorocarbon rubber (FKM) od -34°C do +260°C
  • Fluorosilicone rubber (FVMK) od -73°C do +177°C.
  • Polytetrafluoroethylene (PTFE) od -196°C do +260°C.
Low temperature
  • The coefficient of linear thermal expansion of rubber materials is approximately ten times higher than that of steel.
  • At low temperatures, the rubber material loses its dimensions, loses its flexibility and increases its stiffness.
  • At extremely low temperatures, the material changes to a glassy state with no elasticity and maximum stiffness.
High temperature
  • By exceeding the upper limit temperature, rubber materials soften and lose their physical properties.
  • Continuous exposure to higher temperatures permanently damages the seals. 
  • Physical properties with long-term exposure are not reversible. Rubber materials take on a permanent deformation of their previous shape.
  • PTFE material does not contain plasticizers and volatile ingredients and is stable at temperatures below +300°C.
  • It is stable under simultaneous exposure to heat and aggressive chemicals.

Elastomeric material, Rubber

In aerospace and defense applications, many designs include rubber seals. Therefore, it is important that many parameters such as permanent deformation after compaction, media compatibility, speed, application temperature range, tolerances, etc. keep under control. Our quality assurance and 100% batch testing,  ensure that the manufactured materials are in accordance with the specifications.

Here we have provided details of the rubber materials recommended for use in these applications. Other materials are available. For more details contact us…

Material Code Suitable Rubber Base Hardness (Shore A) Temperature Range (oC) Reference Specification Media Type Specification or Media Name Application Information
N7173 NBR 70 -54 to + 135 MIL-P-25732
Petroleum AMG –10
Hydraulic oil Low
temp. (HUNT-S)
Landing gear shock strut, Hydraulic oil Installations
N7093 NBR 75 -54 to + 135 MIL-P-25732
Petroleum MIL-PRF-5606
(NATO H-515)
Aero Shall Fluid 4
Landing gear shock strut, Hydraulic oil Installations
N7188 NBR 80 -54 to + 135 MIL-P-25732
Petroleum MIL-PRF-5606
(NATO H-515)
Aero Shall Fluid 4
Landing gear shock strut, Hydraulic oil Installations
F9727 FPM 80 -20 to + 230 SNO7196
Kerosene Jet Fuel; JP-4,
JP-5, Jet-A
Aviation Fuel Applications

Material Polytetrafluoroethylene, PTFE

Very common solutions in application are composite seals in which, in addition to the rubber element, we also find PTFE materials as an integral part of the solution. This applications requires the highest quality pure PTFE material and also its numerous mixtures with mineral ingredients and additives. These compounds improve the basic properties of PTFE material to meet the high demands of working conditions such as linear speeds of coupled parts, very low or extremely high working temperatures, chemical compatibility of the material and the environment, etc.

Material Code Tensile strength
Elongation (%) Hardness (Shore D) Specific Gravity (g/cm3) Color Description and Applications
T1001 40 380 58 2.16 white Additive:Virgin PTFE
Profile: Low pressure,low friction, clean systems
Surface: Steel, Chrome
T1004 27 250 63 3.08 Greyish
to dark brovn
Additive: Bronze (medium filled)
Profile: Extrusion resistance,Hydraulic/pneumatic applications.Notsuitable for water and insulation applications.
Surface: Hardened Steel, Chrome, Cast iron
T1010 18 200 60 3.91 Light
to dark
Additive: Bronze (high-filled)
Profile: Very high extrusion resistance and compressive strength, for linear lubricating motions.
Surface: Hardened Steel, Chrome,Cast iron
T1014 15 150 63 2.1 Black Additive: Carbon/Grafite
Profile: Medium and high loads, V-rings Packings,Compressor ring. Ideal for water applications
Surfaces: Steel, Chrome
T1015 20 200 61 2.4 Black Additive: Grafite
Profile:  Very low wear on hard metals.Gude ring for chock absorbers
Surface: Hardened steel, Chrome
1016 23 300 62 2.2 Black Additive: Glass fiber (15%)
Profile:  Piston Rings, Buchings, Excellent abrasion and high pressure resistance
Surface: Hardened steel, Chrome
T1021 20 260 62 2.24 Black Additive: Glass fibers/MoS2
Profile: Rotary applications, Lip Seals, Dynamic Seals
Surface: Hardened steel, Chrome
T1030 22 250 62 2.09 Grey Additive: Carbon fiber
Profile: Long wear life, High pressure
Surface: Steel, Chrome plating
T1035 15 200 60 1.94 Grey Additive: Polyimid
Profile: Piston rings and Sealing elements, Self-lubricating bearing
Surface: Steel, Chrome plating