Ampco® 18: Durable, Conductive, and Ideal for
High-Wear Moulding Applications
When it comes to blow mould tooling, not all metals are created equal. At Beaubury, we carefully select materials that offer the right balance of performance, cost, and durability — and one alloy we regularly work with is Ampco® 18. Known for its unique blend of strength and thermal conductivity, it plays a precise but vital role in the tools we design and manufacture.
What is Ampco® 18?
Ampco® 18 is a high-strength aluminium bronze alloy, developed by AMPCO METAL. It’s part of a family of copper-based alloys engineered for tough industrial applications — from aerospace bushings to heavy-duty tooling components.
What sets Ampco® 18 apart is its ability to combine mechanical durability with excellent heat transfer. This makes it particularly valuable in applications where thermal cycling is rapid, and surface wear is high.
Because it contains no beryllium, it’s safer to machine and handle compared to traditional beryllium-copper alternatives.
Key properties of Ampco® 18:
Hardness: ~34 HRC (Rockwell C), much harder than standard bronzes
Tensile Strength: Up to ~800 MPa
Thermal Conductivity: ~60 W/m·K (significantly higher than tool steels)
Non-sparking, non-magnetic, and beryllium-free
Resistant to galling, deformation, and thermal fatigue
Where and How We Use It at Beaubury
Rather than machining entire moulds or tools from Ampco® 18, we use it selectively — integrating it into aluminium-based or modular tooling setups where its properties have the most impact.
1. Bite Edge Overlays in Aluminium Body Blocks
Aluminium is excellent for blow mould bodies — it’s lightweight, cools rapidly, and is easy to machine. But it’s not strong enough to handle repeated force at bite edges or parting lines, where wear and deformation are common over time.
To solve this, we machine Ampco® 18 inserts or overlays into these high-stress areas. This delivers:
Better edge durability under pressure
Cleaner parting lines and reduced flash
Longer-lasting tools with no sacrifice in cycle time
It’s a smart hybrid approach that keeps tools light and fast — without compromising integrity at their most vulnerable points.
2. Neck Blocks
We also use Ampco® 18 in neck blocks, where durability and dimensional stability are essential. The material resists galling, holds tight tolerances, and performs reliably over repeated use — especially in high-volume production.
Its good machinability also makes it ideal for custom profiles and complex geometries, helping to maintain consistent neck finishes across cycles.
3. Blowpin Tips (Ampco Variants)
While Ampco® 18 isn’t always the best fit for blowpins themselves (which may require different characteristics like lower friction or specific thermal profiles), we occasionally use Ampcoloy® variants — part of the same material family — for blowpin tips or specialist applications.
These tips often require:
High thermal conductivity for fast cooling
Sufficient surface hardness to resist wear
Smooth release and minimal sticking
Materials like Ampcoloy® 940 or 972 offer those properties in a form optimised for blowpin functionality, providing the same family-level advantages as Ampco® 18, but tuned for the specific job.
Why This Material Strategy Works
By using Ampco® 18 only where it’s needed — rather than overengineering an entire tool — we give our clients:
Reduced weight and faster cooling from aluminium bodies
Targeted durability at bite points and high-contact zones
Optimised cost and machining time, without performance compromises
This also makes maintenance and refurbishment easier. In many cases, we can simply replace worn Ampco® inserts without scrapping the entire tool — extending the life of the main body and reducing downtime.
In Summary
Ampco® 18 is a precision solution — not a catch-all material. At Beaubury, we use it strategically where high thermal conductivity and mechanical strength need to work side by side: overlays in aluminium blocks, robust neck tooling, and (in some cases) adapted variants for blowpin components.
It’s part of a wider philosophy we bring to tooling — matching materials to function, not tradition — and ensuring our clients get tools that perform better, last longer, and run faster.
