Low Melt Fusible Alloy 70
The Industry Standard for Precision Tube Bending
DKL Low Melt 70 (commonly known as Wood’s Metal) is a high-purity, Bismuth-based fusible alloy engineered for delicate industrial processes. While versatile, it is primarily specified as a premium tube bending alloy. Its unique physical property of expanding slightly upon solidification provides essential internal support for thin-walled tubes, preventing kinking, wrinkling, or collapsing during complex manipulation.
Tube Bending
Provides rigid internal support for bending thin-walled sections. Easily removed by immersion in hot water.
Safety Systems
A sharp 70°C melting point makes it ideal for fire sprinkler heads and heat-activated safety valves.
Work Holding
The alloy’s expansion ensures a secure “lock” for holding irregular parts during precision machining.
Technical Specifications
| Physical Property | Value |
|---|---|
| Melting Point (Eutectic) | 70°C (158°F) |
| Density | 9.4 g/cm³ |
| Tensile Strength | 24.7 MPa |
| Hardness (Brinell) | 7.2 |
| Thermal Conductivity | 0.188 j/cm sec °C |
| Recommended Pour | 75°C – 85°C |
Need to convert Celsius to Fahrenheit for your process?
Technical Data & Composition
Chemical Composition (Nominal) +
- Bismuth (Bi): 50%
- Lead (Pb): 27%
- Tin (Sn): 13%
- Cadmium (Cd): 10%
Dimensional Stability & Growth +
Unlike standard solders that shrink, Low Melt 70 expands after casting. This is critical for tooling and pipe-bending accuracy:
- Growth after 5 Mins: +0.27%
- Growth after 30 Mins: +0.45%
- Growth after 1 Hour: +0.51%
Availability & Formats +
DKL Metals manufactures this alloy in the UK to ISO 9001:2015 standards. It is available in:
- Blowpipe Strips: Approx 85g
- Tinmans Sticks: Approx 250g
- Large Bars: 1kg weight
Batch Consistency+
Our in-house Spectro-Analysis ensures consistency for safety-critical thermal links.
Note: These alloys contain Lead and Cadmium. They are intended for RoHS-exempt industrial applications, such as tube bending, safety thermal links, and specialised tooling.
Frequently Asked Questions
What are the alternative names for Wood’s Metal? +
Low Melt 70 is known globally by several industry trade names. Depending on your region or legacy technical specifications, it may be referred to as:
- Cerrobend
- WR Bendalloy
- Ostalloy 158
- Fry’s Fusible No 2
DKL Metals manufactures this alloy to meet the eutectic 70°C specification required for these trade names.
How do you use a low melting point alloy for tube bending? +
To prevent kinking, the low melting point alloy for tube bending is melted and poured into the tube. Because it expands upon cooling, it provides internal support. Once the bend is complete, the assembly is placed in hot water to safely melt and remove the alloy for reuse.
Is this the correct fusible alloy for fire sprinkler systems? +
Yes. Low Melt 70 is a primary fusible alloy for fire sprinkler systems and safety thermal links. Its eutectic nature ensures it remains completely solid until it reaches 70°C, providing a reliable and rapid release mechanism.
What is the Bismuth-based alloy dimensional stability after casting? +
A key feature of Bismuth-based alloy dimensional stability is its unique growth property. Unlike most metals, this alloy expands by approximately 0.51% within one hour of casting, ensuring a tight mechanical grip for machining fixtures and tooling.
Where to buy Wood’s Metal in the UK for industrial use? +
If you are looking for where to buy Wood’s Metal in the UK, DKL Metals manufactures high-purity fusible alloys at our Grangemouth facility, supplying formats from 85g blowpipe strips to 1kg bars.