HT800 Washers

Here at Advanced Seals and Gaskets Ltd we manufacture and supply 1000’s of washers produced from a variety of silicone sponge materials, in various densities and grades.    One such material is HT800 Silicone sponge, which is a medium firmness sponge with flame retardant properties,  manufactured at 915mm wide, and in standard thicknesses ranging from 0.8mm - 12.7mm, at various roll lengths from which washers can be cut. 

HT800 washers are manufactured on-site using drawings or measurements provided by our customers, with whom we work closely to ensure the final product is to their exact specification.  Depending upon the size and quantity of washers required, one of many presses or CNC machines can be used to manufacture the final product - from one-off samples to multiple thousand batches runs, we have a machine designed to quickly and accurately produce perfectly formed washers every time.   

On-site conversion facilities mean we can stock and supply rolls and sheets ready for despatch or use them to further convert into multiple usable finished parts including washers - all supplied plain or laminated with a choice of one of our many self-adhesives or foils.

What are HT800 Silicone Sponge Washers?

HT800 is a closed-cell, lightweight, versatile, medium firmness, flame retardant silicone sponge that offers enhanced sealing capabilities and is used in applications where fire safety is a concern as the material will offer low levels of flame propagation, low smoke generation and low emission of toxic gases. 

The closed-cell structure of the HT800 sponge means it can be used in sealing applications against dust, moisture and air making it a great material for washer production. 

HT800 Sponge Washers are a flat ring with an outer diameter (OD) and inner diameter (ID) measurement, cut from a sheet of material which is placed between two surfaces creating a level surface, acting as a spacer, seal or between nuts and bolts to spread the pressure when tightened. 

Ht800 Washers

Product Enquiry

For information on HT800 Washers please complete the following quick enquiry or call us on +44(0)1384 252555.






    Product Specification & Key Characteristics

    • Colour: Grey, Red, Black
    • Resistances:  UV, ozone and fire 
    • Flammability: Flame retardant to UL94 HF1 and V-0, Low smoke, Meets flame and smoke toxicity ratings and the highest UL, railway, and aerospace standards  (BS6853 Cat 1A approved for use in rail vehicles and is LUL (London Underground) approved for use on the London Underground network)
    • Temperature range of -55° to +200°
    • Standard thicknesses: from 0.8mm to 12.7mm
    • FDA compliant

    Full technical data can be supplied upon request,
    or downloaded from our online portal.

    Help and guidance

    If you would like to speak to a representative to discuss your specific application or requirements please call our sales office direct on 01384 469100, alternatively you can send an E-mail. Simply click on the link and forward us your details along with your question and we will contact you immediately.

    Samples - Technical HT800 Washers

    Samples can be submitted for testing upon request.

    Call now for sample requests or further help.

    Why use HT800 Silicone Sponge Washers?

    HT800 Silicone sponge washers offer many desirable properties with many of our customers choosing this grade of silicone as it has all the properties of standard silicone sponge but is also formulated to be flame retardant and FDA approved. 

    HT800 silicone sponge washers offer excellent heat resistance and are resistant to UV light, ozone and most moderate chemicals. 

    HT800 silicone can be taken in complete roll or sheet form or as pre-cut parts such as washers which can be used to seal against the intrusion of dust, moisture and air in HVAC, electrical enclosures or lighting systems or as shock and vibration cushioning in transport.

    Benefits of using HT800 Silicone Sponge

    • Lightweight, durable and versatile material
    • Excellent memory, how stress relation and good compression set
    • Closed-cell structure creates an excellent seal
    • UV, Ozone and Flame resistant 
    • Meets flame and smoke toxicity ratings and the highest UL, railway, and aerospace standards  (BS6853 Cat 1A approved for use in rail vehicles and is LUL (London Underground) approved for use on the London Underground network)
    • Easily converted into a range of products

    Advantages of using HT800 Silicone Washers

    There are many advantages to using HT800 Silicone sponge washers such as their highly efficient sealing capabilities,  resistance to UV, Ozone, extreme temperatures and fire, making them suitable for a range of uses both indoors and out.  

    HT800 silicone washers can be found widely used for applications such as outdoor sealing where it protects against the penetration of air, dust, moisture such as in lighting fixtures, air conditioning units, electrical cabinets and other outdoor enclosures.

    Due to its compression set, HT800 is also well suited for use in shock absorbing and vibration isolation in a range of electronics and transport applications, and they demonstrate excellent memory and low-stress relaxation, which in turn reduces costs from seal or washer failure caused by poor compression set and softening.

    Different Grades of Silicone Sponge Available

    High-Temperature Sponge is a medium density silicone spine that is soft and pliable, used in a range of sealing and gasketing applications where a temperature range of -60°C to +270°C (300°C intermittently) is required.

    Fluorosilicone Sponge is a blue, closed-cell material that is resistant to oil, harsh chemicals, fuels and solvents.  It has an impressive operating temperature range of -62°C to +204°C, a low compression set and electrical strength 

    Thermally Conductive Silicone is a closed cell sponge that offers thermal conductivity and electrical isolation properties, found used in applications where a thermal transfer is required.

    High Recovery Silicone Sponge is manufactured with a  fine fabric finish on both sides, in a choice of red oxide or black colours  This closed cell sponge is popular with clothing and fabric printers because of its density and easy release properties.

    FDA Sponge is a medium density, closed-cell silicone, white in colour.  This particular grade of silicone sponge is platinum cured to conform to FDA 177.2600 and EC 1935/2004 standards for use as gasketing and sealing in food, drink and pharmaceutical applications.

    Have a Question about HT800 Washers?

    Please contact us using the form below or by calling us on +44(0)1384 252555.