AS9100 Aerospace Bonded Washers & Industrial Bonded Washers
Bonded Washer Seals are also known as Dowty Seals or Dowty Bonded Washers. They are high pressure seals typically used in the Mechanical, Hydraulic and Pneumatic applications.
Our bonded washers consist of a metal rectangular outer washer with a trapezoid shaped rubber ring bonded to the inner of the ring creating a 1-piece washer with an internal seal. Bonded washers hold a large amount of burst pressure whilst retaining the inner seal shape and limiting deformation resulting in brilliant sealing under high pressures.
There are 3 components to a Bonded Washer: the rubber or elastomer, the metal and the finish. View the most common options for your Bonded Washer:
EMI Seals & Gaskets Ltd can supply either the Standard style or a Self-Centering style that eliminates the potential of the being slightly seal offset during installation thus simplifying the process. These seals are readily available in Imperial sizes from 1/8 inch to 3 inches. French and German Metric form part of our extensive stock. Imperial and metric size charts can be found at the top of our data sheets below. The inner bonded rubber seal can be manufactured to suit the end user’s application from the following:
| EMI Ref | Elastomer Name | STANDARD HARDNESS Shore A |
|---|---|---|
| 301 | Silicone (VMQ) | 75°±5 |
| 302 | Fluorosilicone (FVMQ) | 75°±5 |
| 303 | Fluorocarbon (VITON®) FKM | 75°±5 |
| 306 | Ethylene Propylene (EPM & EPDM) | 85°±5 |
| 307 | Styrene Butadiene Rubber (SBR) | 70°±5 |
| 309 | Nitrile (Acronitrile-Isoprene) (IIR) | 85°±5 |
| 309-2 | Hydrogenated Nitrile Butadiene Rubber (HNBR) | 80°±3 |
The above are common materials. Other materials and
shore hardness’s available upon request.
| EMI Ref | METAL | TENSILE STRENGTH* | SPECIFICATION |
|---|---|---|---|
| 3005 | Mild Steel Pressings | 540 | BS 1449 Part 1 CS4 BRH5 |
| 3008 | Mild Steel Turned | 540 | BS 970 Part 1 EN8 |
| 5303 | Stainless Steel Pressings | 540 | BS 1449 Part 2 T316 |
| 5302 | Stainless Steel Turned | 540 | BS 970 Part 1 T303 |
| 5316 | Stainless Steel Turned | 540 | BS 970 Part 1 T316 |
| 5304 | Stainless Steel Turned | 540 | BS 970 Part 1 T304 |
| 2104 | Brass Turned | 380 | BS 2874 CA104 |
| 2108 | Brass Pressings | 380 | BS 2870 CZ108 |
| 1104 | Aluminium Bronze Turned | 700 | BS 2874 CA104 |
| 1101 | Aluminium Alloy Pressed | 370 | |
| 1102 | Aluminium Alloy Turned | 370 | L102 & L168 |
| 4154 | High Tensile Steel | 880 | S154 |
| 1030 | Aluminium Alloy Turned | 370 | HE 30 (6086-T6) |
*TENSILE STRENGTH MN/m2 (MINIMUM)
The above are the most common metals. Others available upon request.
| EMI Ref | SURFACE FINISH | SPECIFICATION |
|---|---|---|
| 00 | No Surface Finish | |
| 01 | Zinc Plating | Def. STAN. 03-20 |
| 02 | Gold Passivate | Def. STAN. 03-33 |
| 03 | Cadmium Plating | Def. STAN. 03-19 |
| 04 | Chromic Anodise | Def. STAN. 03-24/2 |
| 05 | Sulphuric Anodise | Def. STAN. 03-25/2 |
| 06 | Clear Passivate | Fe/Zn-5CIA |
| 07 | Zinc/Cobalt & Colour Passivate | ZnCb-921/ST140 |
| 08 | Mechanical Zinc Plate | STD.5735,114 Fe/Zn 8 C1 |
| 09 | 09 Zinc/Iron and Black Chromate | Fe/Zn – Fe 5 C4 |
| 10 | Sherardize 2000 | SHS 1091 |
| 11 | Chromium Plate | CR3 |
Custom Grades including MilSpec, Def STAN, AS & DTD available.