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Deburring AND OR Edge breaking.....same thing?

dkmc

Diamond
I asked the Laser cutting vendor:
"Would you also be able to quote the cost for deburring / breaking the edges on the parts"?

And they replied:
[FONT=&quot]My price includes deburring all the parts. These parts are too small for our edge breaking machine.[/FONT]

So the parts come in with no actual burrs sticking up but sharp 90 deg. edges. As far as I know, laser cutting doesn't generate burrs. I thought the parts would show up not needing the edges deburred/broke based on the above statement. And didn't allow for time to deburr in my quote. I guess it's a play on words to differentiate between "de burr" and "edge break" as there's a fine line (pun intended) between the two? Do most people take the meaning of Deburr and Edge break to be two different aspects of part geometry?
[FONT=&quot]
What say ye?
[/FONT]
 

crossthread

Titanium
Joined
Aug 5, 2004
Location
Richmond,VA,USA
This is just my opinion because I don't know the technical difference. Someone will probably chime in. To me deburring is just to get rid of a burr left over from some operation. I would consider just a hand deburring tool to be used here. In my opinion, edge breaking is a bit more aggressive and if I am truly breaking the edge, then I use the mill or something similar to machine a small chamfer on the part.
 

IninefingersI

Aluminum
Joined
Mar 9, 2022
Location
Doo Dah, Kansas
One of the standard general drawing notes in the airplane business is "Deburr and Break Sharp Edges." The definition of an acceptable edge break in our manufacturing spec is .005 - .015. A burr is anything that you can catch with your thumbnail. An edge break is just removing the sharp edge. Deburring a laser cut part would probably be removing any dross.
 

dkmc

Diamond
One of the standard general drawing notes in the airplane business is "Deburr and Break Sharp Edges." The definition of an acceptable edge break in our manufacturing spec is .005 - .015. A burr is anything that you can catch with your thumbnail. An edge break is just removing the sharp edge. Deburring a laser cut part would probably be removing any dross.

So which is it, Red or Green?
 

IninefingersI

Aluminum
Joined
Mar 9, 2022
Location
Doo Dah, Kansas
So which is it, Red or Green?

It is both. That is the range QA has to consider the sharp edge properly removed.

EDIT: My error. You caught me misquoting my own spec. It just lists the maximum edge break, the minimum isn't defined.

2.0 Requirements
Unless specified otherwise on the engineering drawing, all parts and assemblies shall comply with this specification.

2.1 Edges

2.1.1 Jagged, burred, cut or cracked edges and similar types of roughness must be removed from sheet metal parts and extrusions by grinding, filing, or some other satisfactory method. Inside corner over-cuts or cracks shall be ground or cut out.

2.1.2 Deburr and break all sharp edges. Max chamfer (fillet optional) shall be .015 inch max. All edges of sheet metal parts and of extrusions (other than the extruded edges) shall be deburred to remove sharp edges.

2.1.3 Laser cut parts shall have edges that meet the requirements of 2.1.1 & 2.2.2.

2.2 Internal Radii

2.2.1 The radius for a sharp internal corner shall not be less than .06 inch or greater than .16 inch unless specifically indicated on the drawing.

2.2.2 Bend relief cutouts shall be made as specified on the engineering drawing.
 

in2glamisgirl

Aluminum
Joined
Jun 20, 2006
Location
Hawthorne, CA USA
Deburring is one of the subjective areas that different inspection personal will have an opposite opinion on the same part.
Different industries can have significantly varying needs and requirements.

We use this document from SME for deburring guidance. It was provided to our inspection department by an senior Raytheon quality engineer. I have cut and pasted the descriptive part of the doc. below.



This guideline is based on the Worldwide Burr Technology Committee’s Standard WBTC—STD14.1997. It is compatible with ANSI / ASME Y14.5 requirements for clear definition of expectations.
Knowledge of burr and edge terminology is crucial to understanding these directions and maintain consistency in production and inspection efforts. Inspection of deburring is to be performed by visual examination without magnification unless otherwise specified. For further clarification see The Deburring and Edge Finishing Handbook (Society of Manufacturing Engineers, LaRoux Gillespie 1999 Library of Congress #98-061356)
If nonstandard deburring and inspection criteria are required, they should be clearly defined on the part drawing.
The seven common deburring requirements are:
1. Deburring not required: All edges may be left as produced by the sequence of production processes used. Burrs or similar projections produced at edges may cause some dimensions to fall outside their normal limits. This level of edge quality allows producers to remove burrs and finish edges if they desire to do so.

2. Break sharp edges and remove burrs: Edges will be smooth to the extent that hands will not be cut. Burrs may still remain on the products; they may be beaten over, flattened, completely removed, or rounded.

3. Remove burrs and break sharp edges .XXX max: Edges may be chamfered, blunted, or smoothed up to the edge distance tolerance specified. No projections visible to the unaided eye are permitted beyond the normal plane of adjacent surfaces. Small projections that are too small to be detected by normal unaided vision may remain. Any remaining material should not cause dimensions to fall out of drawing specifications.

4. Remove all burrs visible at __ X magnification: No projections visible at __ X magnification are permitted beyond the normal plane of adjacent surfaces. Small projections that are too small to be detected by the indicated power of magnification may remain. This specification level also requires that edges should not be sharp to the extent that they could cut hands. This level of edge quality allows inspection by any quality of optics and any form of lighting. Tactile or other non-optical inspection approaches are not allowed in this level of deburring.

5. Break edges __ X __ minimum: Edges should be chamfered, blunted, or smoothed such that no material falls above a chamfer of the indicated minimum dimensions.

6. Round edges __ to __ radius: Edges should have a curvature falling within the indicated limits. Chamfers are not acceptable.

7. Do not deburr: Edges should be left as produced by the sequence that produced them. This statement explicitly prohibits deburring.
If not explicitly specified by drawings or manufacturing instructions, all edges that garner positive inspection should be broken to a maximum of 0.030 in., and no burrs or sharp edges capable of cutting hands should be visible with the unaided eye. Small projections that are too small to be detected by normal unaided vision may remain. Any remaining material should not cause dimensions to fall out of drawing specifications. (Inspection can only accept or reject to drawing requirements Ref. ANSI / ASME Y14.5.)

Form: DB14.51997 revised
 

mhajicek

Titanium
Joined
May 11, 2017
Location
Minneapolis, MN, USA
A laser cut part can have a small burr on the backside. Flat sanding would remove this, leaving a sharp, burr-free edge. A corner break is making that edge no longer sharp.

When I cut a mold block, the desired edges of the cavity at the parting line are sharp and burr-free. I generally achieve this by skimming the parting line again after cutting the cavity, with the cutter climb-cutting into the material, to shear off any burrs without generating new ones.

Parts to be laser welded are often specified to be sharp but burr-free at the edge to be welded, so that filler rod is not needed.
 

guythatbrews

Hot Rolled
Joined
Dec 14, 2017
Location
MO, USA
My best customer's title block allows "break edges .000-.030." Radius, angle, a mix, manufacturer's choice.

They have allowed little ambiguity and it works great. As stated previously they sometimes add a note "no burrs allowed under XXX magnification", which does allow individual acuity into the mix, always an issue.

I think your laser vendor should have said they broke edges .000 to .xxx to indicate they might leave a sharp edge. I believe they were a bit disingenuous.
 

CarbideBob

Diamond
Joined
Jan 14, 2007
Location
Flushing/Flint, Michigan
My best customer's title block allows "break edges .000-.030." Radius, angle, a mix, manufacturer's choice.

They have allowed little ambiguity and it works great.
So razor sharp is fine with zero at the low limit?
At 1000x do those things you shave with have burrs or just not a great edge?
If there are voids is this holes and trenches or are the high ones burrs?
Rabbit hole.
I used to get prints from a very big carbide supplier that said "No chips allowed on these edges". I told them that they needed to get a bit more specific.
Bob
 

guythatbrews

Hot Rolled
Joined
Dec 14, 2017
Location
MO, USA
So razor sharp is fine with zero at the low limit?
At 1000x do those things you shave with have burrs or just not a great edge?
If there are voids is this holes and trenches or are the high ones burrs?
Rabbit hole.
I used to get prints from a very big carbide supplier that said "No chips allowed on these edges". I told them that they needed to get a bit more specific.
Bob

Yes sharp is fine for these little parts. If it is not they put a hi and low limit on the break and specify angle or radius.

And right you are. This is indeed a rabbit hole, but this customer is very pragmatic.. Occassionally they will specify burr free under a certain magnification, and I daresay nothing is burr free under a high enough magnification.

I'm reminded of the disgruntled little guy on the burr bench that said he thought I'd be happy if we could make parts with no burrs and put him out of a job. He was right!

Volumes have been written on this topic. I haven't read them all (or even many) and I'm certainly no burr expert.

I agree If needs must some kind of objective requirements are of course essential, and communication with your customer is very helpful.
 

eKretz

Diamond; Mod Squad
Joined
Mar 27, 2005
Location
Northwest Indiana, USA
At 1000x do those things you shave with have burrs or just not a great edge?
If there are voids is this holes and trenches or are the high ones burrs?

A good razor edge should not have a burr or you will not be shaving with it for long. A very high quality razor blade actually looks pretty darn good at 1,000x. Attached are a couple microscope images I took of a new Feather disposable straight razor blade. The darkfield image gives a pretty good idea of the edge straightness. That is amazingly good at 1,000x.

Differential Interference Contrast, 1,000x optical magnification:
20220503_230109.jpg

Darkfield, 1,000x optical magnification:
20220503_230132.jpg

The photos aren't perfect, they're just taken through the microscope eyepiece with my phone camera, but they give you a pretty good idea.
 

dkmc

Diamond
Word trickery is what it feels like from the email they sent (see post #1). Live and learn. I didn't add in any time to deburr-break edges to my customers quote as I thought the edges would be 'broken' and not sharp. I know for next time I guess. A bit frustrating. I'll "throw them in the rocks" (vibe deburr) for a couple hours and see how they look. Hopefully won't need further hand work.

I think your laser vendor should have said they broke edges .000 to .xxx to indicate they might leave a sharp edge. I believe they were a bit disingenuous.
 

guythatbrews

Hot Rolled
Joined
Dec 14, 2017
Location
MO, USA
A good razor edge should not have a burr or you will not be shaving with it for long. A very high quality razor blade actually looks pretty darn good at 1,000x. Attached are a couple microscope images I took of a new Feather disposable straight razor blade. The darkfield image gives a pretty good idea of the edge straightness. That is amazingly good at 1,000x.

Differential Interference Contrast, 1,000x optical magnification:
View attachment 348539

Darkfield, 1,000x optical magnification:
View attachment 348540

The photos aren't perfect, they're just taken through the microscope eyepiece with my phone camera, but they give you a pretty good idea.

Feathers are my blade of choice. Glad to see it confirmed.

Just curious what microscope did you use? Pics are very cool.
 








 
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