What Is Graining in Metal Fabrication?
If you’ve done any kind of home improvement project or worked closely with wood in any capacity, you’ve surely heard about graining. The grain in some woods is more uniform than others and working “against the grain” can be a real challenge.
But what about grain in metal fabrication? Even if you’ve heard the term, maybe you’re not quite sure what it means or how the process works.
In this article, we’re going to take a closer look at what grain in metal is, why it’s so important, and what the process of graining looks like.
Understanding Grain in Metal Composition
Most metals are polycrystalline. That simply means that they’re solid and composed of differing crystallites. Collectively, these crystallites are referred to as the metal’s grain. Individually, they’re microscopic but collectively, they form the grain of the metal.
As metal is processed, the alignment and direction of crystallites are altered causing the metal to have a preferred grain orientation.
Why is Grain So Important?
Understanding and determining grain direction in the fabricating process is essential to understanding how the metal will behave and what the effects will be on its strength and structural integrity.
A Closer Look at the Graining Process
Graining involves the use of coated abrasives to remove a top layer from metal blanks. Typically done with a sanding belt, grits are normally 120, 180, or 220. Once the initial sanding process is complete, some metals may need to be softened with a surface sander to achieve the desired appearance and grain orientation.
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Why Graining is So Important
Determining grain size in metal is extremely important. Generally speaking, the smaller the grain size, the stronger the metal will be.
Getting this part of the process correct is critical if metals are going to be bent in a tight radius.
Metals with larger grain sizes can’t be bent in tight radiuses and are much more susceptible to failure.
Working With Grain
The direction in which you work with the grain is another important factor in the process.
When you’re working with aluminum, for example, it’s vital to know whether you’re working with the grain (longitudinal) or across it (transverse).
Whatever the case may be, the grain will always move in the direction the metal was milled.
When is the Graining Process Most Applicable?
Like virtually all applications of metal fabrication, graining is common across a wide variety of industries. The most common ones include the military, aerospace, audio, telecommunications, and medical devices to name a few.
Final Thoughts
The process of the graining isn’t inherently complicated. However, if it’s overlooked it can lead to structural failure of the metal involved.
If you have additional questions about graining and how it might be useful in your next metal fabrication endeavor, reach out to the friendly folks at Meta Fab. Our seasoned metal fabrication experts are standing by, ready to assist you however they can.