Deburring is the removal of burrs, the small raised edges and loose slivers of material left behind where a cutting tool exits a part. On machined parts, deburring and edge break requirements are set by the drawing, and they matter because burrs can interfere with assembly, damage seals, cut hands, and break loose inside systems.
Deburring is often treated as an afterthought, but it can take a significant share of the labor on a complex part. This page explains where burrs come from, how machine shops remove them, and how to specify edge conditions clearly.
Where burrs come from
Burrs form when the cutting tool pushes material ahead of it rather than shearing it cleanly. They are most common where a tool exits the part:
- Where drilled holes break into cross holes or exit a face.
- At the start and end of threads.
- Along milled edges and the tops of slots and pockets.
- At part-off on lathes, where the part separates from the bar.
Ductile materials such as austenitic stainless, copper, and some aluminum alloys tend to form larger burrs than brass or free-machining steels. Plastics can leave fuzzy or stringy edges.
How machine shops remove burrs
| Method | How it works | Typical use |
|---|---|---|
| In-machine chamfer or deburr tool | Programmed chamfer pass on edges during machining | External edges, hole entries, repeat production |
| Hand deburring | Deburr blades, files, and abrasives at the bench | Cross holes, complex edges, low quantities |
| Abrasive brushing | Brushes remove light burrs from edges and threads | Light burrs on turned and milled parts |
| Mass finishing (tumbling or vibratory) | Parts processed in media to round edges | High quantities where uniform edge rounding is acceptable |
| Thermal or electrochemical deburring | Specialized processes for internal burrs | Hard-to-reach internal intersections; outside processing |
Designing a chamfer into the drawing, rather than relying on hand deburring, lets the shop cut the edge condition in the machine, which is more consistent and usually cheaper.
How to specify edge break on a drawing
Common drawing notes include "Break all sharp edges" and "Remove all burrs." These are useful but vague. A clearer note gives a size range, such as:
- "Break sharp edges 0.005 to 0.015 in unless otherwise specified."
- "All edges burr free; break edges 0.010 in max."
- "Sharp edge required" on specific edges that must not be broken, such as a sealing or cutting edge.
If an internal intersection, such as a cross hole in a hydraulic manifold, must be burr free for cleanliness, call it out specifically so the shop plans the method and inspection.
Why deburring affects cost
Hand deburring is manual labor on every part. A part with many cross holes or intricate edges can take longer to deburr than to machine. Specifying consistent chamfer sizes lets the shop program them, and avoiding unnecessary internal intersections reduces work that can only be done by hand.
Burrs in specific materials and features
Threads deserve particular attention. A burr on the first thread can stop a gage or gall a mating fastener, so thread entries are usually chamfered or countersunk. Cross holes in hydraulic and pneumatic parts can shed burrs into a system, which is why many fluid-power drawings call internal intersections burr free. Soft materials such as copper and pure aluminum tend to roll burrs over rather than cut them off, and those burrs can hide inside holes.
Deburring and inspection
Edges are typically inspected visually and by touch, with magnification for small features. Chamfer size can be checked on an optical comparator or with gages. For cleanliness-critical parts, the drawing or PO should state the acceptance criteria. Wexmar checks chamfers and edge profiles on its optical comparator where required; see inspection and quality.
Deburring at Wexmar
At Wexmar, edges are chamfered in the machine where the geometry allows, on CNC lathes, Swiss-type machines, and horizontal machining centers, and finished by hand at the bench where needed. Specialized processes such as thermal deburring are arranged through qualified outside processors if a drawing requires them. See our capabilities page for the processes run in-house.
Deburring checklist for your drawing
- Default edge break note with a size range.
- Sharp edges that must stay sharp identified.
- Chamfers dimensioned where a consistent edge is needed.
- Internal burr-free requirements called out on specific features.
- Cleanliness acceptance criteria stated if applicable.
Getting a quote
Include your edge break and burr requirements in the drawing notes so they are priced correctly. You can upload a drawing for an instant estimate or call (315) 400-2654 to talk to an estimator.