1. MR80- 722
1PaPER
MF EE *D TE ICI MR EM PE
INDEXTERMS
Deburring
CostEffectiveness
Productivity
SOClEiYOF
MANUFACTURING
ENGINEERS
ONESMEDRIVE
l?O.BOX930
DEARBORN
MICHIGAN,48128
DEBURRING:THESLEEPINGGIANT
BY
Henry‘Hank”Schaaf
DeburringConsultant
SchaafAssociates
ABSTRACT
This paperdiscusseswhydeburring, which hasgenerally
beenthought of asa minor portionof manufacturinganda
necessaryevil, while quietlygrowingto becomeoneof
industries majorproblems can beconsideredI’A Sleeping
Giant.II It attemptsto givea betterunderstandingof
deburringin general, it’s potentialandhowto bestutilize
it. In addition,it pointsout someof industries problems
pertainingto deburringandofferssolutionsthat can provide
substantialcostsavingsto a smallaswell asa largecompany.
Creative Manufacturing Engineering Programs
2. ABSTRACT
This paper discusses why deburring, which has generalty been thought
of as a minor portion of manufacturing and a necessary evil, while quietly
growing to become one of industries major problems, can be considered “A
Sleeping Giant”. It attempts to give a better understanding of deburring
in general, its potential and how to best utilize it.
In addition, it points out some of industries’problems pertaining to
deburring and offers solutions that can provide substantial cost savings
to a small as well as a large company.
INTRODUCTION
It is obvious that every company large and small is interested in in-
creasing productivity and decreasing manufacturing costs. Al though many
companies do not know their deburring costs, the majority of those who do
know agree that in many cases, it is a significant portion of their total
cost of manufacturing.
Also, it is clear to those who take the time to look that, in most
cases, the greatest area for improvement can be found in their deburring
department.
It is a proven fact that the addition of properly applied deburring
equipment can afford a greater increase in productivity and decrease in
cost than in any other area of a manufacturing facility. In addition,
deburring equipment generally requires less time to amortize than the ma-
jori ty of production equipment.
Many people, engineering societies and trade publications have de-
voted thousands of hours and reams of paper to the subject of deburring.
Furthermore, there have been numerous Deburring Conferences and Trade Shows
throughout the world with the express purpose of educating industry.
MRSO-722
3. -2-
With all of this effort and publicity, deburring is generally under-
rated by industry. It is sti Ii a “necessary evi 1” in the eyes of many pro-
duction supervisors and executives. They authorize large capital expendi- I
tures for production equipment and fight the purchase of deburring machinery
tooth and nail.
The first question is: “Why hasn’t the deburring field been more suc-
cessful in their endeavors to enlighten these decision makers?“. To this
writer the answer is obvious. We are not reaching this segment of industry.
It is inconceivable that management, whose major concern is “The bottom
I ine”, would knowingly take this backward attitude, when it is a proven
fact that improvements in a deburring area can afford the greatest cost
savings in a manufacturing faci I i ty.
The second question is: “Why is deburring probably the most neglected
field in the metal working industry as a whole?“. The answer to this ques-
tion along with the solutions to both questions are almost as complex as the
deburring field itself.
In order to intelligently confront these problems, it is first neces-
sary to obtain a proper perspective of the over-all picture. This includes
an analogy of two fields, old and new, and their acceptance by the metal
working industry, a general insight as to what the deburring field encom-
passes and catagorizing industry into sizes that have common problems.
COMPARE DEBURRING TO QUALITY CONTROL
Quality Control,prior to World War II, was unknown in the metalworking
industry. Inspection was the word and parts were inspected to insure that
certain requirements were met.
After World War II, the government pressed for some formal inspection
method that would produce uniformity and collect relevant data and at the
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same time solve a cost problem. QC as it is known today was then intro-
duced to the metalworking industry. In the beginning it too had its dru-
thers and frustrations. Manufacturing personnel thought it was hog-wash
and due to the lack of understanding, did not believe in its principals or
its claim of being a helpful tool to manufacturing, both to increase pro-
duction and reduce both manufacturing and inspection costs. Such words
and phrases as random samples, AQL sampling plans, and the use of statis-
tics, in many cases, proved to afford tremendous cost savings over the old
100% inspection.
Today QC is a by word in industry. Even the small shop owners have
QC manuals. Whether they utilize QC to its fullest or not, they are fully
aware of QC and how they must comply.
In the large companies QC in many cases is equal in stature to Pro-
duction, Engineering, Sales and all other major departments that make up
the organization.
The irony of this is that one of QC’s problems and major reasons for
rejection are burrs and surface finish.
DEBURR ING
Oeburring, by definition of one of the major manufacturers of indus-
trial compounds and abrasives, is the removal of burrs. It sounds so sim-
ple but, as this text will point out, actually deburring is a vast and com-
plex field that encompasses not only burr removal, but also radius forming,
descaling and surface finishing.
It is as old as machining, engineering, sales and other fields com-
prising industry. It is only natural that those in the field are frus-
trated by the general lack of acknowledgement that it is a major field.
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This is exemplified in that:
1. There are very few engineers, in comparison,
devoting full time to deburring.
2. Engineering schools have no specialties in
deburring.
3. Very few companies have training programs to
increase the skills of burr hands.
DEBURRING METHODS
Let’s take a look at some of the more common methods of deburring and
surface finishing.
1. Hand deburring utilizes manual labor to perform
various hand operations ranging from the medial
unskilled to the highly skilled microscopic
deburring.
Although the equipment found in any given deburr-
ing operation will vary greatly, they all have one
or more of the following pieces of equipment in
common.
(A) Sanding, buffing and/or wire brushing
machines
(B) Polishing lathes
(C) Hand grinders and burrs
(D) A variety of files, hand scrapers, emery
paper, etc., etc..
2. Mass finishing
The success of any mass finishing process depends
upon an understanding of the process parameters and
MR80- 722
6. -5-
that mass finishing along with many other deburring
methods is not a science. Optimum results are
ultimately established from trial and error, or
“cut and try“ as it is commonly referred to.
The following parameters, in various combinations
are common to all the mass finishing techniques:
The drive speed, number of parts, size, shape,
type and volume of media, volume of water and the
type and quantity of compound are the process para-
meters which, used in various combinations, are
common to all mass finishing processes.
(A) Vibratory finishing is a highly controllable
and the most common of the four major mass
finishing techniques. The basic principle
is that vibratory forces are introduced to
the media and parts setting the entire load
into motion at the same time. This al lows
the media to act against the parts through-
out the complete mass which results in a
process which is 2 to 10 times faster and
in many cases produces more uniform fini-
shes than conventional barrel finishing.
(B) Barrel finishing/Tumbling is the con-
trolled processing in a rotating barrel.
As the barrel rotates the parts and media
are carried upward together to a turnover
point at which time the mass stops its
MR80- 722
7. -6
upward movement and slides toward the
lower part of the barrel. This slide
zone is where the abrasive action takes
place and represents approximately 15
to 25% of the load at any given time.
(C) Centrifugal barrel finishing utilizes
a number of drums mounted on or near
the periphery of a larger drum or
turret. The turret rotates at a
high speed in one direction while
the smaller drums are rotated at
a lower speed in the opposite dir-
ection. This motion creates a high
centrifugal force (averaging 25 g’s)
causing the parts to slide against the
media in a tight compacted mass which
results in a very short cycle time.
(0) Spindle finishing utilizes a rotating
tub containing abrasive media. Parts
are fixtured onto rotating spindles
which are immersed into the rapid
moving abrasive slurry near the
periphery of the tub. Good control
and a high degree of uniformity are
characteristics of this process.
Naturally it is slower since parts
must be fixtured, but in cases where
MR80- 722
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the other mass finishing techniques
are not applicable, it can produce
excellent results.
3. Abrasive blasting
A media is propelled through a jet to the part or parts.
Velocity, direction and time together with the tyne
of media and the carrier are process parameters.
(A) Dry blasting
(B) Wet blasting
(C) Glass beading
(0) Micro abrasive blasting
4. Abrasive flow
A part is fixtured between two media chambers. Hydrau-
lic pressure propells a viscous, semi-solid abrasive
laden media from the first chamber thru the fixture
and the part or parts to another chamber. This action
is followed by flow reversal.
5. Electrochemical
(A) Electrochemical deburring (ECD)
Parts are fixtured and the
burrs are dissolved by introducing
an electrolytic action. This pro-
cess is primarily used for hard to
get at internal burrs and where
applicable is a versatile and cost
reducing process.
MR80- 722
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(B) Electropol ish
Parts are bath dipped usually
in an acid electrolyte. It is the
reverse of plating and is used
mainly for micro finish improve-
ment and producing a high lustre.
6. Thermal deburring
Parts are placed in a chamber which is then pressurized
with a gas fuel and oxygen mixture and ignited. The
ignition produces instantaneous high heat and fire
which burns the burrs away. Where applicable, and
the cost can be justified, this process is probably
the fastest of all known deburring methods.
7. Chemical
(A) Chemical etch
(B) Chemical and electrochemical - some-
times used in conjunction with the
mass finishing techniques to
accelerate the deburring cycle.
It should be obvious that deburring is a large and very diversified
field encompassing a number of technologies such as abrasives, compounds
and media, all of which are separate and distinct fields of their own.
INDUSTRY’ S BURR RELATED PROBLEMS
Industry in general is made up of companies ranginq from the very
large, in both employees and dollar volume, down to the one man shop. For
the purpose of this text, industry will be categorized as large companies
(2000 or more employees), medium companies (100 to 1999employees) and small
MR80- 722
10. -9-
companies (1 to 99).
Large companies generally have monies available for capital expendi-
tures, can afford a well staffed Engineerinq department and talent. The
majority of companies in this category have some of the following problems
in common.
1. improving deburring methods low on priority list.
2. insufficient manufacturing engineering personnel
assigned to deburring problems.
3. Lack of productive time. M E’s spending excessive
time putting out fires and fighting paper mills.
4. Duplication of efforts due to lack of comunication.
5. Inability or fear to make decisions.
6. Lack of knowledge of new technology.
7. Lack of trained personnel.
8. Growing pains.
9. Lack of motivation.
Small companies, on the other hand, rarely have adequate funds avail-
able for capital expenditures nor can they afford the luxury of sufficient
talent. Most of these companies are also plagued with a number of problems
common to small businesses.
1. Supervisory personnel wear too many hats - spread too
thin.
2. Many small shop owners originally worked in the shop
of large companies and are not familiar with many of
the necessary functions performed prior to a job
reaching the production area. It is surprising how
many small companies do not include deburring cost
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into their quotes.
3. Lack of knowledge in the deburrinq field.
4. Underestimate deburring.
5. Growing pains.
The medium size companies, unfortunately,
problems of the small companies while at the s,
the problems existing in the large companies.
The answer to the second question, “Why i
have inherited many of the
!
ame time, obtaining some of
s deburring probably the
most neglected field in the metal working industry as a whole?“, should
now be apparent.
The majority of industry’s burr related problems can be reduced to
the lack of time and change vs. stability.
1. Time is no doubt the major problem not only in
industry but in every endeavor in our fast moving
world. Whether it be an individual or a large
corporation, the first priority is survival, which
means making money. This encompasses acqui ring
orders, producing and delivering goods or services
in order to be monetarily renumerated.
Deburring is only one cog in the wheel and
rightfully must take its place on the priority list
of time utilization. Unfortunately, as we have
stated before, the field is so multi-faceted and
complex that many companies cannot afford the
time necessary in order to make the right deci-
sions on matters of deburrinq methods and equip-
ment. As a result, in the majority of cases,
MRSO- 722
12. -ll-
very little or nothing is accomplished.
2. Change vs. stabi I i ty has plaqued human beings in
genera 1, from nations down to individuals since time
began. To change or make changes creates a feel ing
of instability and therefore, it is only natural for
people to resist change, even though, in reality,
the opposite is true. In order for us to grow and
gain stability we must progress and constantly make
changes for the better.
Resistance to change is a disease affecting not
only the deburring field but every phase of industry.
Those in the deburring field can ask, “What good are
all the sophisticated machining centers if the parts
they produce are stacked to the ceiling awaiting to
be deburred?“, until they are blue in the face.
They will still hear many people give such answers
as:
“I know we need this equipment but we have
other priori ties.”
or
“Delivery is past due and I don’t have time
to investigate better deburring methods.”
or
“We have been deburring these parts for many
years and we don’t have any problems.”
or
The classic, “You can’t reduce our deburring
MR80- 722
13. -12-
costs. Our deburring department
only cost us $3.50 per hour per
person .”
SOLUTIONS
These “pennywi se, pound fool i sh” answers are far more common than most
people realize. The solution lies in education and motivation. In the
small companies this is far easier said than done.
In the larger companies this can only be accomplished from a progres-
sive top management level which is also a monumental task. It is not easy
to stifle such employee cancers as:
1. “My job will be safe iF I stay out of sight, out of
mind.”
2. “I’m just coasting until retirement so why make waves.”
3. “My bosses don’ t seem to care, so why should I .I’
The solution to the utilization of time is easier to solve. There is
a great deal of excellent technical information available on deburring
which allows management and engineering personnel with limited deburring
knowledge to compare different types of equipment to fit his particular
needs.
There is a large number of reputable distributors who either have, or
have access to, persons extremely knowledgeable in the deburring field.
In addition, there are a growing number of consultants specializing
in deburring. They offer industry not only a wealth of knowledge of the
processes and available equipment but an unbiased appraisal of the over-all
deburring operation with recommendations as to the most economical approach
to meet the necessary requirements and afford the greatest cost savings.
MR80- 722
14. -13-
Time does not permit the enterprising businessman to physically accom-
plish everything themselves.
1. They don’t Fill out their tixes and financial papers.
Instead they acquire the services of an accountant.
2. They do not make a study of available insurance
policies necessary to the business. Instead they
put their trust into someone with expertise in
the insurance field.
3. They don’t spend their time taking courses in law
in order to comply with all the laws and legal
matters of their business. They hire lawyers with
expertise in a specialized area of law.
Obviously, these approaches are only common sense. Why is it that
when it comes to deburring the following approaches are so prevalent?
1. The owner of a small shop, in order to ship parts,
sets at a bench until all hours of the night hand
deburring.
2. Management personnel place deburring problems on the
back burner because they have too many other things
to do.
3. Many hours consumed in meetings discussing ways of
reducing costs without even mentioning the deburring
operation, and if they do, it is usually shot down
as being insignificant, underestimated or there is
no one available with the time to investigate the
situation.
MRSO-722
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4. Hundreds of man hours spent in visiting Trade Shows,
sending for manufacturer’s literature, interviewing
salespersons and analyzing all the data compiled
only to find out that there is a better way.
Being aware of how complex the deburring field is, coupled with the
real possibility of substantially reducing cost and increasing productivity
in this area, isn’t it only sensible to utilize the services and expertise
of those people knowledgeable in the deburring field? In essence - call a
deburring doctor.
CONCLUSION
People who comprise industry, whether it be the small shop owners,
mid-level supervisor, or the corporate executive, must begin to realize
that deburring is a large, complex field that is continually becoming more
prevalent and sophisticated as technology advances.
Deburring is not only here to stay, but unless its importance is real-
ized and progressive action is taken, it will act as a cancer until the
company is no longer competitive in the market place.
BIBLIOGRAPHY
Bernard Hignett, “Mass Finishing”, Metal Finishing July and August 1978
Robert N. Stauffer, “What you should know about Vibratory Finishing”,
Manufacturing Engineering, July 1979
Henry “Hank” Schaaf, “Save production time, money with new ECD process”,
Machine and Tool Blue Book, April 1978
LaRoux K. Gi 1 lespie, “Deburring Capabilities and Limitations”, Published
by SME 1976
H. W. “Bill” Allstun, Manufacture’s Service Inc. S. El Monte, Calif.
MR80-722
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