Buy Sealing & Cushioning Washers Online in Australia
AIMS Industrial stocks 17 sealing and cushioning washers from Champion and Mackay, covering two genuinely different jobs: sealing washers (Dowty/bonded seal, copper, aluminium and rubber washers that create a leak-free face seal on hydraulic, BSP and drain-plug fittings) and cushioning washers (steel Mackay washers that distribute load, stop overload and limit travel on vibration isolator mounts). They look similar but do unrelated jobs — get the wrong one and you'll either leak oil or damage an isolator, so we've split them clearly below. Not sure which one suits your job? Our Types of Washers: Flat, Spring, Lock, Structural & Sealing Explained covers selection in detail.
Quick Reference
| Type | Material | Sizing | Used for |
|---|---|---|---|
| Dowty Seal Washer (BSP) | Steel outer ring + bonded NBR rubber | BSP thread sizes | BSP hydraulic & plumbing face seals |
| Bonded Seal (CDW) Washer — Metric | Steel outer ring + bonded NBR rubber | Metric thread sizes | Metric-ported hydraulic pumps & valves |
| Copper Sealing Washer | Soft annealed copper | Single sizes & 5-size packs | Banjo bolts, drain plugs — single-use crush seal |
| Copper Crush Sealing Washer | Soft annealed copper | Fitting-specific | Crush-seal drain plug & banjo applications |
| Aluminium Sealing Washer | Soft aluminium | M20 x 26 x 2mm (25/pack) | Drain plugs, fuel fittings — copper alternative |
| Rubber Sealing Washer / Drain Plug Seal | Rubber | 22 x 28 x 5mm (25/pack) & drain-plug specific; 4-size pack | Light-duty plumbing & drain plug seals |
| Cushioning Washer (Recessed Flange / Overload / Snubbing) | Stainless steel | Isolator-model specific | Vibration isolator mount hardware — not a fluid seal |
Sealing Washers — Dowty, Bonded, Copper & Rubber
Sealing washers create a leak-free face seal on hydraulic fittings, BSP connections, banjo bolts, drain plugs and fuel-line fittings, removing the need for thread sealant on a face-sealing port. AIMS stocks Champion's Dowty seal, bonded (CDW), copper, aluminium and rubber sealing washer ranges, individually and in assortment kits.
Dowty Seal & Bonded (CDW) Washers
A Dowty seal washer — also called a bonded seal — is a steel outer ring with a rubber lip bonded to the inner face. Tightening the fitting compresses the rubber against both the port face and the washer's metal ring, giving a reliable face seal without thread sealant. Champion's Dowty washers are stocked in BSP thread sizes; the CDW bonded seal is the metric equivalent, used on metric-ported hydraulic pumps and valves. Because the seal works on the flat port face rather than the thread, it only suits parallel threads (BSPP, metric parallel) — a tapered thread (BSPT, NPT) has no flat face for a bonded seal to compress against, and needs PTFE tape or an anaerobic thread sealant instead. Champion's metric range is also available as a 91-piece assortment kit (CA174) and a 173-piece master kit (CA2173) for workshops that don't want to hold open stock of every size.
Copper & Aluminium Sealing Washers
Champion copper sealing washers (including the CSW1218, CWC1218 copper crush washer and the CDP26 five-size pack) are soft-metal crush seals for banjo bolts, drain plugs and fuel system fittings. The copper anneals and deforms slightly under torque, conforming to minor surface irregularities at the joint face — which is exactly why it's a single-use seal: once crushed, it won't seal reliably a second time. The M20 x 26 x 2mm aluminium sealing washer (ASW2026) does the same job as an alternative where copper isn't specified or on hand.
Rubber Sealing Washers
The CDP25 rubber seal washer pack, RSW2228 (22 x 28 x 5mm) and CRW1220 rubber drain plug seal suit lighter-duty plumbing and drain-plug sealing where a metal crush washer isn't required.
Cushioning Washers — Vibration Isolator Mount Hardware
The four Mackay washers in this range are a different product entirely — stainless steel hardware washers used with vibration isolators, not fluid seals. They don't provide the cushioning themselves (that's the isolator's job); they protect and control it:
- Recessed Flange Washer / Recessed Flange Steel Washer (M15286, M181550C) — sits under the mounting bolt on a flanged isolator, spreading clamping load evenly across the flange face so the isolator isn't crushed or distorted as the bolt is tightened.
- Overload Washer (M18409A) — a hard stop that limits how far an isolator can deflect under a transient overload, such as a machinery start-up surge, protecting it from permanent deformation.
- Snubbing Washer (M16911) — limits vertical travel on an isolator under shock loading, keeping it aligned and stopping it from bottoming out — useful on mobile and portable equipment during transport.
Match a cushioning washer to the specific isolator model it's fitted to, and confirm the bolt size and flange/recess dimensions before ordering — see our Anti-Vibration Mounts range for the isolators themselves.
Selecting the Right Washer
For sealing washers: confirm the port thread (BSP or metric) and whether it's parallel or tapered, then match the washer's inside diameter to the fitting's thread and its outside diameter to the port boss face. If replacing an existing seal, measure the old washer's inside and outside diameter and match a new one of the same size and material. Copper and aluminium crush washers should always be replaced when a fitting is undone, not reused. For cushioning washers, match to the isolator model and mounting bolt size, and confirm the flange or recess geometry is compatible before fitting.
Brands Stocked
Champion supplies the Dowty, bonded, copper, aluminium and rubber sealing washer range. Mackay, an Australian rubber engineering brand, supplies the recessed flange, overload and snubbing cushioning washers used with vibration isolator mounts.
Companion Ranges
- Hydraulic Fittings — matching parallel-thread fittings for Dowty and bonded seals
- O-Rings and O-Ring Kits — face-seal and dynamic seal alternatives
- Fibre Washers — compressed-fibre gasket washers for general plumbing
- Flat & Round Washers — standard flat washers for general fastening
- Anti-Vibration Mounts — the isolators our cushioning washers are fitted to
- Hydraulics — pumps, valves and hydraulic componentry
Not sure which sealing or cushioning washer suits your fitting or isolator? Call our team on (02) 9773 0122, get in touch via our contact page, or request a quote for bulk or trade pricing.
FAQs — Sealing & Cushioning Washers
Q: What is a Dowty seal (bonded seal) washer?
A steel outer ring with a rubber lip bonded to the inner face. Tightening the fitting compresses the rubber against the port face and the washer's ring, giving a leak-free face seal on BSP or metric hydraulic ports without thread sealant.
Q: What's the difference between a Dowty/bonded seal and a copper sealing washer?
A Dowty or bonded seal is reusable across multiple assemblies provided the rubber lip is undamaged. A copper sealing washer is single-use — it's a soft-metal crush seal that deforms permanently under torque and must be replaced every time the fitting is undone.
Q: Can a copper sealing washer be reused?
No. The seal relies on the copper crushing under torque to fill surface irregularities at the joint. Once crushed and removed, it won't seal reliably on reassembly — always fit a new one.
Q: What's a cushioning washer used for?
Cushioning washers are stainless steel hardware fitted alongside vibration isolator mounts — not a fluid seal. They distribute clamping load across the isolator flange, act as an overload hard-stop, or limit travel under shock loading, depending on the type.
Q: What's the difference between an overload washer and a snubbing washer?
Both protect a vibration isolator from excess movement. An overload washer acts as a hard stop against transient overload, such as a machinery start-up surge. A snubbing washer limits vertical travel under shock loading and keeps the isolator aligned — useful on mobile equipment during transport.
Q: Why can't a Dowty seal be used on a tapered thread port?
A Dowty seal is a face seal — it compresses against the flat face of the port boss. A tapered thread (BSPT, NPT) seals on the thread engagement itself and has no flat face for the washer to compress against, so fitting one there leaks under pressure. Use PTFE tape or an anaerobic thread sealant on tapered threads instead.
Q: When would I use an aluminium or rubber sealing washer instead of copper?
Aluminium sealing washers do the same crush-seal job as copper on drain plugs and fuel fittings, and are a useful alternative where copper isn't on hand. Rubber sealing washers and drain plug seals suit lighter-duty plumbing seals where a metal crush washer isn't required.
Q: What sizes do Champion's bonded seal assortment kits come in?
The metric bonded seal range is available as a 91-piece assortment kit (CA174) and a 173-piece master kit (CA2173), covering the most common metric sizes for hydraulic pumps and valves.
Q: How do I identify the correct sealing washer size?
Match the washer's inside diameter to the fitting thread size and the outside diameter to the port boss face. If replacing an existing washer, measure the old one's inside and outside diameter and match a new one of the same size and material.
Q: Does AIMS stock Mackay washers as well as Champion?
Yes — Mackay supplies the recessed flange, overload and snubbing cushioning washers used with vibration isolator mounts, alongside Champion's sealing washer range.