What Machine Shops Should Understand About Deburring

Whenever a manual or machine tool cuts metal, imperfections called “burrs” can occur. When a tool modifies a part, whether by drilling a hole, filing an edge, or cutting a shape, the tool displaces and reshapes bits of material. However, this doesn’t always remove all the material affected, leaving burrs on the part. These burrs could cause the part to fail to perform or meet specifications, resulting in rejection.

Why It’s Important

Machine shops need to know about deburring because they work to meet the specifications their clients provide, and those specifications will likely include precise deburring requirements.

Before they can begin, machine shops need to determine specifications for edge radius, surface finish, and stock loss. They will also consider changes in the dimension or mass of the part due to the deburring process. All these can vary depending on the type of material the shop works on and the size of the part the shop is making.

According to Gillespie, ideally, manufacturing and deburring should take place in one machining operation that:

• Uses sharp tools and appropriate feed rates
• Uses planned machining steps to address how to minimize burrs, or control them so they form on an area of the part where the burr is easy to remove

As a practical matter, the single machining-deburring process is rarely possible. Most machine shops conduct machining first and deburring as a separate finishing process.

The Effect of Different Machines

Machine shops also need to know that vibratory deburring machines will work differently than a rotary barrel or bowl deburring machines. Machine shop managers should always clarify specifications and ask clients for details in writing; what the shop means by “free of visible burrs” may not be acceptable to the client. For example, the client may follow a standard where burrs cannot be seen under a microscope at a specified level of magnification. Shops should also realize that deburring machines are not cure-alls—careful machining is critical to minimize the size and maximize the uniformity of the burrs that inevitably will occur. Then, deburring will produce parts that are of an acceptable standard of quality.

For example, micro parts have edges measured in millimeters. Some types of vibratory deburring machines will be suitable for small parts and capable of producing refinements down to millimeter sizes. However, others could trap small parts in gaps within the vibratory chamber, specifically between the finisher’s moving parts and its walls or surfaces. This could result in parts that don’t meet specifications and will be rejected.

If you’re not sure which type of deburring machine is right for your job, contact AccuBrass for help. We can explain the different options available that might work for your shop.