GlossaryKind of term: Manufacturing termDeburring
What is deburring?
Deburring is the removal of burrs and the breaking of sharp edges left by machining or cutting, done in the machine, by hand or in bulk.
A burr is an unwanted ridge of material on an edge. It forms where a cutting edge leaves the material or pushes it ahead. Deburring removes that burr and, where needed, breaks the sharp edge. That can be done in the machine with a chamfer or deburring tool or a brush, by hand with a deburring blade, scraper or file, or in bulk by vibratory finishing or blasting. For cross holes and hard-to-reach edges there are also thermal and electrochemical methods.
What does burr formation depend on?
How large a burr grows depends on the material, the sharpness of the cutting edge, the feed, the angle at which the tool exits and the order of operations. Tough, ductile materials such as aluminium, austenitic stainless steel and many plastics burr more. A well-chosen sequence makes a burr form on an edge that is machined later anyway. Which method works also depends on access: a chamfer cutter only reaches the edges it can get to, and cross holes and edges at the bottom of a pocket often need hand work or another process.
How does deburring work in practice?
On the drawing the requirement appears as a general note, such as ‘break sharp edges’, or as an edge requirement to ISO 13715, which states for all edges or per edge whether a burr is allowed and within which size range. Hand deburring is labour time and is not automatically covered by the machine hourly rate. How long it takes depends on the number of edges and holes, access, the material and the edge requirement. Deburring in the machine costs programming and cycle time but can replace hand work. A set time per edge or per piece as its own item is an estimating convention you can test against actuals.
What is deburring often confused with?
Deburring is not chamfering: a chamfer is a dimensioned form on the drawing, deburring removes what the operation left behind and breaks an edge without a dimensioned form, at most within the range of an edge requirement. It does overlap with finishing: vibratory finishing and blasting can deburr and change the surface at the same time, and with it size and roughness.
Frequently asked questions
Can deburring be done in the machine?
Partly. A chamfer or deburring tool breaks the edges it can reach, at the cost of programming and some cycle time. Edges at the bottom of a pocket, at a cross hole or on the clamped side often stay hand work or need another setup.
How do I price deburring when nobody clocks it?
With a set time per piece based on the number of edges and holes, as its own item beside machining. Compare that norm with the actual time on a few batches and adjust it per part type.
What does ‘break sharp edges’ on a drawing mean?
That no edge may stay sharp or burred, without a size being given. That is not precise. If an edge requirement to ISO 13715 is given, it fixes for all edges or per edge which deviation inwards or outwards is allowed.