No matter the size of your shop or the types of pieces you produce, deburring and finishing is an incredibly important process—polishing formed parts to remove any undesirable flaws and imperfections before further processing or completing them.
From understanding the process to finding the machine that will be just right for your application; this is your go-to guide to metal deburring and finishing.
We start by tackling the basics (how burrs are created, what finishing machines are built to accomplish, and how your shop can develop deburring standards) before moving on to explore some of the benefits of automated deburring and tips for selecting the right finishing machine.
Put simply, finishing and deburring machines are designed to remove imperfections that remain attached to workpieces after they’ve been modified by another machine. These undesirable raised edges are commonly known as burrs, and they fall into one of two categories:
- Mechanical burrs result from operations like shearing, stamping, or folding.
- Thermal burrs, often called slag or dross, are caused by heat-generating machines like laser cutters.
There are a variety of factors that can lead to the formation of burrs including the type and thickness of the metal being worked, condition of the die, blade clearance, and pressure or power exerted by the machine.
Understanding the Differences between Deburring and Finishing
- Deburring involves removing any raised edges or small pieces of material that remain attached to a workpiece after it’s been modified.
- Finishing is done to alter the surface of a workpiece, getting rid of any scaling and pitting to enhance its quality or prepare it for a next step like painting.
Other common operations done with finishing machines can include calibration and stock removal (a machining operation done to achieve higher material removal rates and decrease variations), slag grinding (targeting slag produced by thermal cutting machines), and edge rounding (any action that breaks the edge of a metal part, but especially those that form an edge radius).
Developing Deburring and Finishing Standards
In the majority of cases, each shop sets its own deburring and finishing standards based on individual and customer needs.
To architect regulations for your shop, it’s best to start by breaking the fabrication process down into three stages—design, manufacturing, and inspection—to identify what needs to be done and when it needs to happen.
To begin, you need to have a clear understanding of quality expectations (the edge requirements identified through product drawings).
Typical instructions can include:
- Deburring is not required, meaning edges should be left as they’re produced. Do not deburr is a statement that expressly prohibits any deburring.
- Remove sharp edges so that hands, electrical wires, and mating parts won’t be cut or harmed when they come into contact with the finished piece. Burrs will remain on the piece and can be removed later.
- Remove all visible burrs. Remove clear imperfections (anything that’s too small to be detected by the unaided eye) and sharp edges.
- Remove all burrs visible at [x] magnification, leaving anything that can’t be detected at the indicated power or magnification level. You’ll want to get rid of sharp edges here as well.
- Break edges _x_ mm minimum. In other words, edges should be sloped, blunted, or chamfered so no material falls above a chamfer of the indicated minimum dimensions.
- Round edges to _x_ mm radius. This lets you know that your edges need to have a curvature that falls within the indicated limits, a chamfer being unacceptable.
Whatever classifications your shop uses, it’s crucial to make sure requirements are clear and don’t leave room for doubt.
Make sure that instructions are written to provide information about:
- General- and job-specific definitions and requirements.
- Equipment operation and calibration.
- Deburring and finishing techniques.
This will enable operators to fully understand the parameters for the job at hand while tailoring their approach to ensure they get the best results.
Instructions often outline how inspections should be performed, what standards or requirements need to be met, and how measuring or recording devices should be used.
Common inspection types include:
- Visual: Since eyesight varies between inspectors, this inspection is typically the least precise.
- Tactile: Inspectors can use a range of tools like toothpicks (locates burrs and steps as small as 0.0005 inches), pencils (assesses whether or not a burr is rigidly adhered), and a fingernail (detects burr height and sharpness).
- Magnification or Microscopes: These methods are used to more accurately detect minute amounts of metal.
- Borescope: These tools are used to inspect holes and cavities that can’t be studied with the naked eye.
- Metallurgical Mounts: This technique is typically used only when other approaches don’t produce the desired results.
- Height Gauge: This can be used to detect burr height, but it can’t be used to ascertain thickness.
Remember—establishing deburring and finishing guidelines doesn’t need to be a complicated process. At its heart, it’s about being able to clearly state your design, manufacturing, and inspection requirements so that operators aren’t left with questions about what they need to do at each stage.
Taking the time to establish rules for your shop will help streamline and standardize internal procedures, resulting in more rapid setups and cleaner results.
The Benefits of Automated Deburring and Finishing
Automating your shop’s deburring and finishing processes can bring a range of benefits including:
- Increase Safety: Using a deburring machine will make the process safer from start to finish. For operators, automation eliminates the need for them to be in work zone and minimizes risks for repetitive motion injuries. Deburred parts are also safer to handle after they’re finished.
- Improve Consistency: Automating the process means that quality won’t vary between operators, and it will limit the amount of rework you need to do.
- Attain Higher Quality Finishes: Deburring pieces using a machine ultimately produces better parts.
- Offer New Products: If your shop still deburrs by hand, your capacity is determined by the geometry of individual parts. Automating deburring processes means you can produce and handle more and schedule based on what your machine is capable of accomplishing.
Today, there are a wide variety of machines and machine configurations available to suit individual needs. One of Timesavers’ smallest machines, the Mini Dry-Belt Sander, features a 9 x 48inch abrasive belt capable and is powered by a five horsepower motor, making it ideal for hobbyists and small shops that need a light machine at a great price. Timesavers also offers a variety of larger machines like the 4100-series disc sanding machine and 3100-series wide-belt sander suited to run bigger and more complex jobs, as well as mid-size models and machines specifically engineered to handle small parts.
Consult with an expert to determine which machine will be right for your shop and its needs.
Choosing the Right Deburring and Finishing Machine
When looking at machines for your shop, there are a number of factors you need to take into consideration including wet versus dry, type of abrasive, machine configuration, and workpiece characteristics and quality.
Wet vs. Dry
Dry machines are ideal for shops that consistently grind similar materials like carbon steel. They typically come with lower initial price tags and require less maintenance over the long run, though you will need to invest in some form of dust collection.
If your shop routinely grinds different types of metals, you need to use a wet deburring or finishing machine. This is because the dust created from certain metals like aluminum can be highly flammable, and a spark from grinding steel can cause it to suddenly ignite. Wet machines spray coolant on passing workpieces so that:
- Debris is continuously rinsed so particles can’t accumulate.
- There’s no need to incorporate a dust collection unit, which can decrease the machine’s physical footprint.
- Less heat is produced, making parts cooler to the touch when they emerge.
Both wet and dry deburring machines do need to be cleaned regularly, whether with a vacuum for dry machines or a hose for wet machines, and have their filters emptied. Operators should also inspect things like tension levels or pinch roles and the condition of hardware like bearings, making adjustments, repairs, and replacements as necessary.
Type of Abrasive
Choosing the right abrasive is central to getting the best performance out of your machine. Make sure you pay attention to attributes like the:
- Type (coated, non-woven, etc.)
- Grade (very fine, 120 grit, etc.)
- Mineral (ceramic, aluminum oxide, etc.).
Additionally, you need to consider the pros and cons of belt-, disc-, and brush-style abrasives:
- Belts: These run on drums that loop on a continuous basis. By feeding workpieces onto the belt at slight angles, operators can ensure that the sides as well as leading and trailing edges are effectively deburred. The chief downside of belts is that, while they excel at removing vertical burrs, they do tend to roll excess material over the edges of a workpiece to create lateral burrs. These are relatively easy to remove, but they do require additional processing.
- Discs: Discs are best suited for handling small and sensitive parts, including cladded or galvanized materials. The direction in which the pads rotate creates a swirl-like pattern on the workpiece. This helps to prevent the piece from fracturing when bent, making disc deburring ideal if you need to do subsequent work with a machine like a press brake.
- Brushes: Like discs, brushes work effectively with parts as small as playing cards and delicate parts since they are able to remove burrs without affecting surface coatings like cladding, zinc, or laser film. Brushes also excel at edge rounding—something discs have more trouble with—and are able to complete more complicated 360-degree deburring and finishing tasks.
What’s right for you will ultimately depend on your needs. If you simply need to deburr the sides of your parts, a straightforward belt sander could be ideal. If your needs are more complex or varied, you will need a machine ready to keep pace with those demands.
Workpiece Characteristics and Quality
Attributes to consider here include:
- Part size (thickness, width, length, etc.)
- Material (steel, titanium, aluminum, etc.)
- Coatings (paint, cladding, etc.)
- Finished quality (simply removing vertical burrs vs. delivering medical- or aerospace-grade results)
Each of these factors will play a significant role in helping you determine your shop’s needs and finding the machine suited to them.
Consider small parts, for example. Since many conventional deburring and finishing machines use pinch roles to stabilize parts as they are processed, the minimum part length must be the distance between them (at least one pinch role must be holding onto the part at all times).
So what do you do if the parts your shop runs are too small?
While there are traditional solutions you can try to run small parts in your regular finishing machine (running them in a skeleton, holding them in place with fixtures, or using magnetic chucks), you can also rely on a machine that has been designed specifically to handle small parts like Timesaves’ 1200-series 9” widebelt sander. These pieces of equipment typically employ solutions like sticky belts to hold small parts safely and securely in place.
Would you like to learn more about deburring small parts? Check out our earlier article!
Machine and Head Configuration
Although single-head deburring and finishing machines used to be the dominant norm, today many shops (especially larger ones) choose multi-head or combination machines that use different combinations or belts, brushes, and discs.
When thinking about the head configuration that will suit your needs, take into account:
- Required throughput
- Number of passes
- Machine uptime
- Expected volume
- Desired grain finish
Taking the time to analyze all the factors at play—wet or dry, type and style of abrasive, head configuration, and the characteristics or your workpieces—will help you select a system and machine that can deliver better consistency, superior results, and improved productivity.
Consult with Experts
When in doubt about which type of deburring or finishing machine will be best suited to handle your deburring and finishing needs, consult with a metal fabrication expert assess your options.
In determining who to work with, consider things like:
- Experience: Here, you want to evaluate both how long a company has been in business as well as the types of machines and services they provide. Prioritize suppliers whose offerings align closely with your shop’s needs.
- Manufacturing Partners: You want to work with someone who partners with the right manufacturers—industry leaders like Timesavers. Assess the machines each company distributes, both the range of what they offer as well as the strength of individual partners.
- Services: When you purchase your deburring and finishing machine, you want to know you will be able to maintain it without hassle throughout its lifecycle. Choose a distributor with the parts inventories and service expertise you need to keep your finishing machine at peak performance.
- References: Ask the companies you are considering for information about customers they have previously or are still working with. When did they first become a customer? What types of projects have they worked on? What has the overall experience?
Taking the time to consider these types of topics and questions will help you better understand the landscape ahead of you so you can inform your decision. When it’s time to add a new deburring or finishing machine to your shop’s lineup, you will be able to proceed knowing you found the machine that’s just right for you.
Westway has been the Canadian leader in metal forming machinery since 1972. If you would like to discuss how a Timesavers deburring machine can work for your application, contact Westway today!