# Burr formation

Residual edge material from manufacturing: process-dependent formation, inspection boundaries, prevention and controlled removal.

Reviewed: 2026-11-02

Tags: production, machining, burrs, edge-quality

Two equal 45° chamfers taking **0.20 mm** horizontally from each side of a **5.00 mm** rib leave **4.60 mm** flat land, below an assumed **4.70 mm** minimum. Taking **0.10 mm** per side leaves **4.80 mm**. This checks geometry only. Inspect the actual burr separately: in the second example a **0.08 mm** projection exceeds the local **0.05 mm** limit even though the three-location mean is below it.

A machining burr projects beyond the intended edge. Check its location, attachment and effect on function.

ISO 13715:2017 covers edges of undefined shape. A specified chamfer uses geometric dimensioning. Use the drawing’s edge requirement. [ISO 13715:2017, third edition, March 2017, confirmed 2024](https://www.iso.org/standard/61328.html).

## Describe the edge and the actual defect

Record the operation, entry/exit or intersection location, workpiece material/condition, tool and cutting history. Distinguish projecting material from edge chipping, an intentional chamfer, a loose chip and material adhering to the cutting tool. These observations can coexist but require different explanations.

For a burr, describe height or projection, attachment/root thickness, extent along the edge and accessibility. Define the measurement direction and reference surface. A tall, thin projection and a short, thick attachment are not necessarily equally difficult to remove. XEBEC’s surface-brush selection guidance explicitly considers workpiece material, burr thickness and achievable surface roughness; tool selection is not based on burr height alone. [XEBEC, brush-selection instructions](https://www.xebec-tech.com/instruction_manual/cf/20250303_EN_XEBEC-Brush-Surface_InstructionManual/177446758.html).

Inspect the actual edge, including its concealed side where relevant. A satisfactory visible entrance does not establish the condition at a hole exit or internal intersection. Identify which regions are functional sealing, assembly, fatigue-sensitive or handling edges so that the acceptance method addresses the actual requirement rather than an unspecified appearance preference.

## Formation depends on material, support and tool exit

Near an edge, material can deform instead of separating as intended, and the tool’s exit geometry affects the remaining material. Kumar and Dornfeld’s original face-milling study analyzes tool-edge exit order, geometric conditions and material properties. Its experiments found different burr sizes for different materials while investigating a common geometric criterion. These findings support investigating the tool/workpiece engagement, not transferring one burr size or cutting setting across materials. [Kumar and Dornfeld, *Journal of Manufacturing Processes* 5(2), 2003, pp. 127–142](https://www.sciencedirect.com/science/article/pii/S1526612503700486).

Hole geometry also changes the burr’s location. Min, Dornfeld and Nakao’s drilling study found burr formation on only part of a hole circumference when the exit surface was not perpendicular to the drill path. Its experimentally supported location model applies to the studied angled-exit problem, not a claim that every drilled hole has a uniform ring-shaped burr. [UW–Madison MINLAB, original study summary and 2003 citation](https://min.me.wisc.edu/journals/influence-of-exit-surface-angle-on-drilling-burr-formation/).

Record tool wear, edge condition, engagement, chip evacuation, feed and speed when comparing runs. Avoid treating “reduce feed” or “increase speed” as a universal correction: the relevant cutting and deformation mechanisms, tool type and stability must be identified first.

## Prevent upstream where practical

Sandvik’s **indexable-insert drill** guidance identifies internal cross-hole deburring as difficult. For unequal hole diameters it recommends drilling the larger hole first to reduce burr formation, along with guidance for the crossing engagement. The page separates recommendations for different drill types; retain that boundary when planning a trial. [Sandvik Coromant, irregular-surface drilling, indexable-insert cross-hole section](https://www.sandvik.coromant.com/en-gb/knowledge/drilling/irregular-surface-drilling).

For groove/slot milling, Sandvik warns that thin chips can contribute to vibration, poor surfaces and burr formation and discusses cutter selection accordingly. This is a reason to examine engagement and tooling, not permission to increase feed without checking the cutter’s applicable data. [Sandvik Coromant, groove or slot milling](https://www.sandvik.coromant.com/en-us/knowledge/milling/groove-or-slot-milling).

Operation sequence can also determine whether a later machining operation removes an earlier edge burr or creates a new one on a finished feature. Review the final edge after the complete sequence. A prevention trial should preserve its baseline and change an interpretable variable; evaluate dimensions, edge condition and tool-life behavior together.

## Removal is a controlled operation

Choose removal access and tooling for the actual attachment, substrate and permitted material removal. Mechanical cutting, brushing or other qualified finishing processes are not interchangeable merely because each is called deburring. Consider adjacent surfaces, fixture access, debris removal and the risk of producing another unwanted edge.

XEBEC’s brush instructions require consideration of workpiece size/shape, attachable tool length, cycle time and interference with fixtures or other objects. Their material/thickness selection chart describes that product family; it does not establish acceptance of a finished part or suitability for every internal passage. [XEBEC, brush selection and size](https://www.xebec-tech.com/instruction_manual/cf/20250303_EN_XEBEC-Brush-Surface_InstructionManual/177446758.html).

Removing a burr is not automatically equivalent to adding a chamfer. A defined edge break may be required, permitted or prohibited depending on function. Agree the drawing requirement before replacing an undefined edge with a standard programmed chamfer.

## Original example: removal can consume functional land

Assume an invented rib whose flat top is **5.00 mm wide before edge finishing**. The drawing independently requires at least **4.70 mm of remaining flat land**. Suppose a proposed operation creates equal 45° chamfers on both top edges, each extending **0.20 mm horizontally** into that top surface.

`remaining flat land = 5.00 − 0.20 − 0.20 = 4.60 mm`.

That proposed geometry is **0.10 mm below** the assumed minimum, even if it removes every burr. Reducing each horizontal chamfer extent to **0.10 mm** gives **4.80 mm** of flat land, which satisfies this one geometric requirement. It does not prove burr removal, surface quality or compliance with other dimensions. The calculation assumes an exact starting width and ideal straight chamfers; real tolerances and measurement uncertainty require their own assessment.

For a separate invented inspection example, assume the agreed maximum permitted burr projection is **0.05 mm** at each inspected location. Three measured projections are **0.02, 0.04 and 0.08 mm**. The maximum exceeds the limit by **0.03 mm**. Their average, approximately **0.0467 mm**, cannot establish compliance with a per-location maximum. These values are examples, not recommended burr limits or a statistically sufficient sampling plan.

## Specify acceptance and retain evidence

Define edge locations, permitted projecting material, permitted removal, any required chamfer/radius, loose-material restrictions and inspection access. Use ISO 13715 where its undefined-edge notation fits; explicitly dimension a required geometric shape instead. A general note does not supply all missing functional limits. [ISO 13715:2017 public scope](https://www.iso.org/standard/61328.html).

Select a method capable of observing the relevant direction and location: a single silhouette can miss a projection hidden behind the edge, while an inaccessible intersection may need a qualified alternative method. Establish magnification, lighting, datum/reference, coverage and disposition under the organization’s inspection plan. An absence of visible burrs in one photograph is not proof that every edge is acceptable.

A useful handoff includes material/part revision, manufacturing operation and tool history, burr location/measurements, proposed prevention or removal change, resulting edge dimensions and acceptance results. Keep a promising trial separate from a released production instruction.

## Source versions

Reviewed **2026-11-02 PST**. ISO identifies **13715:2017, edition 3, March 2017**, confirmed in **2024**. The cited original milling and drilling studies are **2003** publications; their bounded findings are not current machine-setting recommendations. No independently verified issue date is assigned to the manufacturer web guidance; XEBEC’s URL and website copyright are not treated as a manual issue date. Numerical examples and handoff recommendations are original assumptions.