A burr is a tiny ridge of metal left after cutting, drilling, or stamping. If you ignore burrs, parts snag during assembly, crack under fatigue, and fail safety audits. This guide explains why burrs form, how to predict them, and which deburring methods return edges to a safe, smooth state.
Indholdsfortegnelse
- Know why burrs happen in cutting
- Types of burrs and where they appear
- Rank materials by burr tendency
- Machining parameters that control burr height
- Manual deburring tools and techniques
- Mechanical deburring processes for volume
- Thermal and electrochemical solutions
- Inspect burr quality with simple gauges
- Cost, time, and edge quality comparison
- Need clean edges fast?
- Final checklist before shipping
Know Why Burrs Happen In Cutting
During the last micron of chip separation, the tool loses support. Work material bends instead of shears, leaving a feather-thin lip. Harder alloys snap clean; softer alloys smear and roll, making taller burrs.
Types Of Burrs And Where They Appear
Each process leaves its own fingerprint. The table links common shop operations to burr style.
| Proces | Burr name | Typical size µm | Risk |
|---|---|---|---|
| Milling exit edge | Poisson burr | 50–150 | Cut fingers in assembly |
| Drilling break-through | Drill cap burr | 80–200 | Fastener mis-seat |
| Blanking punch | Shear rollover | 100–300 | Seal leak path |
| Turning face cut-off | Cut-off nib | 30–120 | Sharp speck in bagging |
| Laser cut sheet | Recast bead | 10–40 | Paint adhesion fail |
Rank Materials By Burr Tendency
A material’s ductility governs burr height. The bar chart shows relative risk.
Soft aluminum ██████████ Mild steel ███████ Brass free-cut ████ Stainless 304 █████ Titanium ███ Cast iron █
Cast iron chips crumble, so burrs stay low. Soft aluminum smears; expect many deburr steps.
Machining Parameters That Control Burr Height
Before buying a fancy deburr cell, tweak feeds and edge prep.
| Parameter change | Effect on burr | Why it works |
|---|---|---|
| Increase feed per tooth by 20 % | ↓ burr height | Chip shears, less rubbing |
| Add wiper land on insert | Flatter exit burr | Supports edge until break |
| Use climb cut not conventional | Smaller exit lip | Compression not tension at end |
| Back-up plate under sheet | ↓ punch burr | Metal shears against solid anvil |
| Pilot drill 118° then 90° step | Breaks burr ring | Steeper chisel splits lip |
Manual Deburring Tools And Techniques
Hand methods suit prototypes or mixed jobs.
- Swivel blade: Spin along edge; good on keyways.
- Half-round file: Push away from you at 45°.
- Scotch-Brite wheel: Light pass removes fine edge on aluminum.
- Scraper: Single-point HSS honed to hook for shallow pockets.
Mechanical Deburring Processes For Volume
When hourly part counts climb, switch to machines.
| Metode | Cycle time | Edge Ra µm | Bedst til |
|---|---|---|---|
| Vibratory tumble | 1–4 h | 1.5 | Many small parts |
| Brush head CNC | 10–60 s/piece | 0.8 | Large plate edges |
| Abrasive flow | 15–45 s | 0.3 | Internal passages |
| High-pressure water | 5–20 s | 1.0 | Delicate fuel rails |
Thermal And Electrochemical Solutions
Hard-to-reach burrs may need specialty methods.
- Thermal deburr (TEM): Fill chamber with oxygen–fuel mix, ignite, flash burns burrs under 20 ms.
- Electrochemical (ECD): Make burr the anode; dissolve in salt solution at 12-15 V, no burr back-wall damage.
- Laser ablation: Pulse fiber laser at 1 kW to vaporize micro-burrs in medical cannulas.
Inspect Burr Quality With Simple Gauges
Visual rules vary by industry, but simple gauges keep checks quick.
| Gauge | Tolerance detected | How to use |
|---|---|---|
| Edge radius card | 0.05–1 mm | Match arc to edge |
| Feeler shim | >0.02 mm burr | Drag along surface |
| Tape snag test | Qualitative | Peel; snag means fail |
| Microscope 30× | Visual height | Check critical bores |
Cost, Time, And Edge Quality Comparison
The bar chart compares three popular methods.
Method Cycle s Unit cost Edge quality index (higher better) Hand blade ████████ $0.10 3 Brush CNC ████ $0.06 6 Thermal pulse ██ $0.18 8
Brush CNC often wins for mid-volume aluminum plates. Thermal shines on complex steel manifolds.
Need Clean Edges Fast?
Our facility machines, deburrs, and finishes metal and plastic parts under one roof—CNC, sheet, and molding options ready. Send your print for a single-step quote.
Final Checklist Before Shipping
- Confirm burr spec—height, radius, or “no snag” instruction.
- Select machine settings to cut burr at the source.
- Pick deburr method that fits volume and geometry.
- Record edge inspection data—radius card and photo.
- Package parts in trays; no metal-to-metal rub that recreates burrs.
Master these steps and your edges will pass glove tests, fit seals, and keep customers safe.
