Bonded Seal (Dowty Seal)
Bonded Seal (also known as Dowty Seal or Dowty Bonded Washer) represents a combination of metal washer and elastomer sealing lip vulcanised to the edge of the metal part to seal bolted connections and mounting elements in all industrial applications e.g. pipe connections and couplings. When the bolted connection is tightened, the sealing lip is pressed against the flat surfaces.
We produce all standard self-centering bonded seals, KDS bonded seals and can also supply Bonded Seal Kits in BSP and metric sizes or custom kits to suit customer requirements.

APPLICATIONS
Bonded seal is applicable to all threaded bolts, studs and clearance holes. With large range of elastomers and metals available, it can works in wide temperature range.
It can be automatically installed. Metal washer with vulcanised sealing body of rubber for sealing of bolt heads and flanges.
BENEFITS
Cost effective solution for bolt/thread sealing
Sealing washers are available for metric and BSP threads
Large range of elastomers and metals available
Concentrically located
Ease of assembly
Typical applications for bonded seal include:
Materials for bonded seal include:
We stocked below Metric and BSP bonded seals, all in self centering NBR lip with steel washer.
Metric series, self centering | ||||||
Auter Ref. | Metric Thread Size | Inside Diameter | Outside Diameter | Metal Thickness | Metal Washer ID | ID between self centering |
C | A | E | B | F | ||
605 | PPM5 | 5.70 | 9.00 | 1.00 | 6.80 | 4.90 |
606 | PPM6 | 6.70 | 10.00 | 1.00 | 8.00 | 5.60 |
612 | PPM8 | 8.70 | 13.00 | 1.00 | 10.40 | 6.40 |
617 | PPM10 | 10.70 | 16.00 | 1.50 | 12.40 | 8.05 |
622 | PPM12 | 12.70 | 18.00 | 1.50 | 14.10 | 9.73 |
627 | PPM14 | 14.70 | 20.00 | 1.50 | 16.40 | 11.38 |
629 | PPM16 | 16.70 | 22.00 | 1.50 | 18.40 | 13.41 |
632 | PPM18 | 18.70 | 25.00 | 1.50 | 20.40 | 14.76 |
633 | PPM20 | 20.70 | 28.00 | 1.50 | 22.50 | 16.76 |
636 | PPM22 | 22.70 | 30.00 | 2.00 | 24.40 | 18.74 |
638 | PPM24 | 24.70 | 32.00 | 2.00 | 26.40 | 20.11 |
640 | PPM27 | 27.70 | 35.00 | 2.00 | 29.40 | 23.30 |
642 | PPM30 | 30.70 | 38.00 | 2.00 | 32.40 | 25.70 |
643 | PPM33 | 33.70 | 42.00 | 2.00 | 35.40 | 28.70 |
645 | PPM36 | 36.70 | 46.00 | 2.00 | 38.70 | 31.10 |
646 | PPM39 | 41.70 | 51.00 | 2.00 | 40.00 | 34.10 |
647 | PPM42 | 42.70 | 53.00 | 2.00 | 45.70 | 38.70 |
649 | PPM48 | 48.70 | 60.00 | 2.00 | 51.70 | 43.70 |
650 | PPM52 | 52.70 | 66.00 | 2.00 | 56.40 | 48.20 |
651 | PPM60 | 60.70 | 75.00 | 2.00 | 63.00 | 56.20 |
BSP series, self centering | ||||||
Auter Ref. | BSP Thread Size | Inside Diameter | Outside Diameter | Metal Thickness | Metal Washer ID | ID between self centering |
C | A | E | B | F | ||
820 | 1/8 BSP | 10,37 | 15,88 | 2,00 | 11,84 | 8,26 |
821 | 1/4 BSP | 13,74 | 20,57 | 2,00 | 15,21 | 11,18 |
823 | 3/8 BSP | 17,28 | 23,80 | 2,00 | 18,75 | 14,76 |
825 | 1/2 BSP | 21,54 | 28,58 | 2,00 | 23,01 | 18,24 |
826 | 5/8 BSP | 23,49 | 31,75 | 2,00 | 34,97 | 20,60 |
827 | 3/4 BSP | 27,05 | 34,93 | 2,00 | 28,53 | 23,83 |
829 | 7/8 BSP | 30,81 | 38,10 | 2,00 | 32,29 | 27,89 |
830 | 1 BSP | 33,89 | 42,80 | 3,20 | 36,88 | 29,92 |
832 | 1 1/4 BSP | 42,93 | 52,38 | 3,20 | 45,93 | 38,45 |
833 | 1 1/2 BSP | 48,44 | 58,60 | 3,20 | 51,39 | 44,45 |
836 | 2 BSP | 60,58 | 73,03 | 3,20 | 63,63 | 56,26 |
KDS Bonded Seal
Type KDS bonded seal is know as bonded seal for banjo fittings from parker, we developed all KDS series from M10/G1/8A to M48/G1 1/2A. Please find the details in the below table.

Profile | Thread size | Inside Diameter | ID Between Centering | Metal Washer ID | Outside Diameter | Metal Thickness | Total Thickness |
KDS-L | M10-G1/8 | 10.30 | 8.30 | 13.10 | 16.00 | 2.50 | 3.30 |
KDS-L | M12 | 12.30 | 10.30 | 15.10 | 18.00 | 3.00 | 4.00 |
KDS-L | M14-G1/4 | 14.30 | 12.30 | 17.10 | 20.00 | 3.00 | 4.00 |
KDS-L | M16-G3/8 | 17.00 | 15.00 | 19.80 | 24.00 | 3.00 | 4.00 |
KDS-I | M18 | 18.30 | 16.30 | 21.10 | 23.90 | 3.00 | 4.00 |
KDS-L | M22-G1/2 | 22.30 | 20.30 | 25.10 | 30.00 | 4.50 | 5.50 |
KDS-L | M26 | 26.30 | 24.00 | 29.40 | 35.00 | 3.50 | 4.50 |
KDS-L | M27-G3/4 | 27.30 | 25.00 | 30.40 | 38.00 | 3.50 | 4.50 |
KDS-L | M33-G1 | 33.60 | 31.40 | 37.30 | 42.00 | 3.50 | 4.80 |
KDS-I | M42-G1.1/4 | 42.40 | 40.40 | 46.70 | 49.90 | 3.50 | 4.80 |
KDS-L | M48-G1.1/2 | 48.40 | 46.40 | 52.70 | 60.00 | 3.50 | 4.80 |