The Charm of Repurposing Files
One of the most rewarding aspects of blacksmithing is transforming a simple piece of metal into a functional or artistic item. When exploring scrap or found materials, a common and often overlooked resource is an old, worn-out file. These tools, once essential for shaping metal, can become valuable raw material for your projects.
Understanding what makes a good file is key. High-quality files are typically crafted from hardenable steels such as 1095 or W1. Conversely, inexpensive or generic files may be made from softer, case-hardened steels, which are generally less suitable for applications requiring high hardness or edge retention. Despite their variability, many of these files can still be useful for certain projects, especially if you know how to identify their properties.
Contents
- Understanding Good Files
- Identifying Poor-Quality Files
- Evaluating Steel Quality
- Heat Treating for Optimal Hardness
The Good Files
Choosing the right file depends largely on your intended use. For projects demanding a durable, hard edge, reputable brands like Nicholson, Simmonds, and French-made Liogier have historically produced reliable, high-quality files. These brands tend to use superior steels that respond well to heat treatment, making them excellent choices for knife-making and other precision tools.
However, it’s worth noting that many manufacturers are now switching to case-hardened steels. These are often more affordable to produce and can perform adequately if processed correctly. For those planning to forge a blade or similar tool, sourcing older, unaltered files can significantly improve your chances of success, as their steel composition is more predictable and amenable to traditional heat-treating methods.
The Bad Files
If a file lacks branding or markings indicating its origin or quality, its suitability becomes uncertain. Files stamped with labels like “made in China,” “Taiwan,” “Korea,” “Mexico,” or “India” are often made from softer steels designed for general use rather than for hardening or edge retention. Using such files for high-performance tools may lead to disappointment, as they are usually not designed to withstand the stresses of forging or cutting.
For beginners or casual projects, these lower-grade files can still serve well for practice or non-critical applications. But if your goal is to craft a reliable, hardened knife or similar tool, it’s advisable to avoid cheap, unidentified files and instead invest in known, quality material.
Assessing Steel Quality: A Practical Approach
While identifying the exact steel composition can be complex, there are practical methods to estimate a file’s suitability for hardening. These techniques help determine whether to proceed with a particular piece of metal, especially if you’re aiming for a hardened, durable end product.
Break Testing
One straightforward method is to perform a break test. Carefully snap off the end of the file to examine the fracture surface. To do this safely, clamp about 1-1/2 inches of the file’s tip in a vise and apply a controlled, firm blow near the clamp. Use safety glasses and wrap the file with a cloth above the clamp to catch any flying shards.
If the steel is properly hardened, the break will be clean, with a dull grey surface showing no shiny spots or deformation. The fracture will be a crisp, smooth crack without bending or shattering into multiple pieces. This indicates that the steel has undergone sufficient hardening and is likely suitable for further heat treatment and forging.
Conversely, a shiny or deformed fracture suggests softer steel or case-hardening, which may not respond well to hardening techniques. This quick test offers valuable insight into whether your material is worth further processing.
Heat Treating for Better Results
For a more definitive assessment, heat treating the material is essential. Begin by annealing the steel to soften it, allowing for easier shaping and testing. Grind a small V-shaped notch about 1/8 inch deep on the tip of the file to reach the core material. Heat the steel until it glows bright cherry red and quench it swiftly in oil. After cooling, attempt to sharpen and test the edge or perform a file test to evaluate its hardness.
This process reveals whether the steel can be hardened and tempered effectively. For more precise results, using a set of hardness testing files—specialized files with known hardness increments—can provide a clear, quantifiable measure of the steel’s hardness. Investing in such tools is highly recommended if you plan to do multiple projects requiring reliable hardening.
Final Tips and Resources
Transforming old files into functional tools is a rewarding challenge that combines understanding material properties with skilled craftsmanship. Many artisans have crafted beautiful knives and tools from rasps and files, embracing their unique patterns and textures. Don’t shy away from experimenting with scrap materials; the end result can be truly one-of-a-kind.
For additional guidance, consider exploring related topics such as how to check the hardness of metal, beginners’ guide to annealing steel, and temperature color charts for steel. These resources will deepen your understanding and improve your success rate in repurposing files effectively.
If you’re searching for high-carbon steel at scrapyards, consult specialized guides to identify promising candidates. With patience and practice, you’ll develop a keen eye for quality materials that are perfect for forging robust, lasting tools.