CUTTING EDGE PROBLEM | BURRS IN MANUFACTURING

A nuisance to every industry, burrs impact product quality, safety, function and longevity. Identifying what causes burr formation, what techniques can be used to minimize or prevent burrs and finally what processes can be used to remove burrs, can impact not only product performance, but also your bottom line.

WHAT ARE BURRS?

Burrs are raised, bumpy or sharp deformations created on a material’s edge when it is cut, machined, welded or 3D printed. The material and production process used impacts the type of burrs formed. The most common types of burrs include:

• • Rollover/Exit Burr – typical when material is being pierced, punched, parted, notched or sheared. One of the most common burrs, it is formed when the machine first engages and pulls the material, causing it to bend or rollover.
  • Tear Burr – occurs when the material tears or deforms rather than being sheared. This is common during the side-milling process.
  • Poisson Burr – formed when material bulges outward or sideways when downward force is applied by a machining tool.
  • Cut-off/Breakout Burr – appears when there is a separation of the work material prior to a cut being complete.

HOW CAN BURRS BE MINIMIZED OR PREVENTED?

While it may not always be possible, there are ways to minimize and prevent burrs from forming, such as:

• • Planning and allowing for large exit angles on edges
  • Using formed or extruded parts rather than machined parts
  • Cast instead of machining edges
  • Ultra high-speed machining when possible
  • Using selective hardening to reduce ductility at the edges (i.e. flame, induction hardening or laser beam)
  • Preventing cutters from exiting the part
  • Using form tools rather than tools that face and turn
  • Isolating burr formation to an area which is easier to deburr
  • Using push-back blanking method on materials such as aluminum, mild steel or stainless steel

HOW ARE BURRS REMOVED?

Burr removal, or deburring removes these imperfections, while also increasing consistency and edge quality, reducing friction and preparing products for ancillary processes – such as anodizing, powder coating and plating.

Multiple processes exist for deburring – such as mechanical, manual, abrasive/bonded abrasive, thermal, or power brushing. The advantage of mechanical deburring using centrifugal barrel finishing (CBF) equipment is in its ability to simultaneously process multiple parts and complete multiple finishing processes – such as deflashing, descaling, radiusing and polishing, saving both time and money.

THE ISO FINISHING PROCESS

Our documented processes are unique to each customer and product, suitable for delicate, intricate parts as small as 3mm³ – in any material. The friction created within rotating barrels with tumbling media, surfactant and water safely removes burrs and creates a superior isotropic surface finish, while preserving initial geometries and meeting the strictest requirements.

The best way to show you first-hand how our finish can become your finish is to process your sample free of charge. Let us show you what we can do.

LET’S GET IT FINISHED.