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subject to continuous high operating speeds

and elevated temperatures. Most motor bear-

ings have the capacity to absorb moderate-

to-heavy thrust loads. It is important that the

manufacturer’s recommendations for servic-

ing this equipment are followed, and no

attempt to substitute, in case of bearing fail-

ure, should be permitted. Replacement parts

should always be identical or equivalent.

Needle Bearings

Plate-cylinder journals are commonly sup-

ported by needle bearings. A needle bearing

is a full-complement roller bearing that has

rollers with a small diameter-to-length ratio,

and uses controlled circumferential clear-

ance rollers. In this application, it is neces-

sary that the plate cylinder journals be hard-

ened, bearing-quality material, since the

journals become the bearing inner race. In

most cases, the hardened bearing journals

are a permanent and integral part of the

plate cylinders.

Needle bearings have three distinct

advantages:

• They have high capacity ratings –

greater than those of a single row ball

or roller bearings of comparable out-

side diameter.

• They permit use of a larger shaft in a

given application.

• They provide anti-friction characteris-

tics in a small cross-section.

Bearing Care and Use

All bearings, plain or roller element,

must be treated and handled as precision

components, which they are. Bearings are

produced with care and must be handled

with care. The operational life of a bearing

is governed by many external factors and

influences, which include bearing installa-

tion, maintenance and lubrication. Ball and

roller bearings are especially susceptible to

damage during installation. Proper bearing

installation is the most critical factor in a

successful bearing application. Bearings

must be kept clean; dirt means damage.

PRESSES AND PRESS EQUIPMENT 143

PRESSES AND PRESS EQUIPMENT 144

Press Maintenance

his chapter, as well as other

chapters of this book, covers

the subject of tolerances and

defines the extremely close

accuracy required in all phases

of the flexographic process in

order to produce top-quality printing at opti-

mum press speeds.

REALITIES OF WEAR ON

PERFORMANCE

The tolerance requirements spelled out for

the flexographic press and its various compo-

nents relate to a new press as it is delivered

by the press builder to the converter’s plant. A

flexographic press is a machine with many

moving parts and even the finest mechanical

assemblies and materials are subject to con-

tinual wear. Continual and uninterrupted

counter-measures are necessary, not only to

maintain the original accuracies but also to

forestall major press breakdowns, which are

almost always due to lack of day-to-day care.

The most effective countermeasures con-

sist of a program of organized and preven-

tive maintenance, an example of which is

defined and outlined in the following para-

graphs. First, consider not only the advan-

tages but also the absolute necessity of a

well-organized and conscientiously followed

maintenance program.

BREAKDOWN MAINTENANCE

Many companies still depend upon a sys-

tem of breakdown maintenance to keep their

equipment running. The press is run day-in

and day-out with the bare minimum of rou-

tine maintenance until an actual breakdown

occurs. The reasoning behind that is, with

the cooperation of the press supplier, emer-

gency repairs that now become necessary

can be made with little loss of production.

The reasons generally advanced for this

type of maintenance, or lack of it, are that

personnel are not available to carry out a

thorough preventative maintenance pro-

gram, or that it is the cheapest way to keep a

press running, or both. However, even a cur-

sory analysis will show the more obvious fal-

lacies of this reasoning.

Since press breakdowns hardly ever occur

while the press is standing idle or at some

other convenient time, every minor or major

breakdown results in unscheduled press

downtime. The cost for press time alone may

run as high as $400 or more per hour, which

does not include the actual cost of produc-

tion losses, as well as the intangibles, such as

the loss of customer good will due to late

deliveries, the need to reschedule subse-

quent runs and all the additional irritations

that are always part of a press breakdown. It

becomes quite apparent, even at this point,

that the scale measuring the cost of prevent-

ing breakdowns rather than curing them is

quickly being tipped in favor of prevention.

There is a further effect of this breakdown

maintenance system that is not as readily

apparent, nor as simple to evaluate cost-wise.

Over the years, however, its corrosive effect

will be many times more costly than even a

series of breakdowns. All mechanical parts

are subject to wear, no matter how small they

may be, over any given period of time. Normal

wear is tremendously accelerated by improp-

er or haphazardly performed maintenance.

PRESSES AND PRESS EQUIPMENT 145

This wear may not be noticeable from day to

day or even from month to month. Never-

theless, under these conditions the original

tolerances of many press components are

gradually but consistently being degraded

with a simultaneous and proportional loss of

press efficiency and print quality. These

effects may not become fully apparent until a

long-range comparison of production quality

control charts reveals the sobering fact that

on any particular print job, the quality has

veered away from the desired standard until

the standards cannot be met unless the press

is operated at reduced speeds or by other less

profitable operating means.

Since breakdown maintenance consists of

a series of emergency and stopgap measures

that must be handled when they occur, and

not during convenient off hours, it becomes

apparent that this method is entirely inade-

quate to keep a press consistently running at

optimum speeds. Also, from a cost perspec-

tive, this approach is not in proportion to the

temporary results it achieves.

PREVENTIVE MAINTENANCE

An organized maintenance program is well

planned, supervised, and conscientiously and

consistently carried out. This type of program

will provide not only for complete day-to-day

routine maintenance, but will anticipate and

eliminate a majority of the causes of press

breakdowns through periodic inspection and

necessary correction of all press components.

Only by organizing all facets of maintenance

and incorporating them into production

scheduling is it possible to achieve the ulti-

mate goal of every printing plant: to keep the

press running at its highest efficiency, at an

accurately predictable hourly cost, without

unscheduled stoppages due to breakdowns.

Management Responsibility

Organizing press maintenance is a man-

agement responsibility. Organized preven-

tive maintenance represents a basic oppor-

tunity for increasing plant efficiency by

keeping equipment running at optimum pro-

duction speeds with minimum unscheduled

stoppages. It must, therefore, be rightfully

classified as a major factor in cost control.

Just as management considers cost control

one of its primary functions in all phases of

the business, it must also consider press

maintenance as highly desirable and neces-

sary, and must exercise good management

techniques to implement preventive mainte-

nance programs.

In order for preventive maintenance to

work, management must support its mainte-

nance program with an adequate budget for

personnel and material. Materials should not

only include day-to-day requirements, such as

lubricants and other items of routine mainte-

nance, but also a spare-parts inventory.

Reasonable amounts of those press parts that

are expected to wear in the normal course of

operation, and those that experience has

shown may be subject to sudden failure, must

be carried in inventory. The cost of such an

inventory of spare parts will be made up

quickly if even one item is available at press-

side immediately when it is needed.

Management must delegate and define

maintenance responsibilities, clearly and

unquestionably. A sufficiently large plant

may warrant the employment of a full-time

maintenance engineer who will be entrusted

with planning a detailed maintenance pro-

gram, delegating specific duties under the

program to available personnel, and hiring

additional personnel if necessary. The main-

tenance engineer must also keep a constant

watch to ensure that the maintenance pro-

gram, as defined and initiated, is being car-

ried out. The engineer must implement and

change the program as the machinery and

product mix changes with plant growth.

In a smaller plant, the production or plant

manager may be assigned the responsibility

of planning and executing the maintenance

146 FLEXOGRAPHY: PRINCIPLES & PRACTICES

program. However, whether the plant is large

or small, the important fact is that manage-

ment must recognize the need for planned

preventive maintenance and initiate an ap-

propriate maintenance program with direct

line responsibility given to the proper individ-

uals to carry out the program effectively.

Communicating

Maintenance Needs

Equally important to the establishment of

an effective preventive maintenance pro-

gram, is a proper means of communication

between management, maintenance person-

nel and the press operators. Press operators

are the most important people in any main-

tenance program, as they alone have day-to-

day contact with the machinery and are the

first to detect any abnormal press condi-

tions. The press operators must have a per-

son with whom they can communicate sim-

ply and directly as to any condition that they

feel may hinder press performance. They

must also have the assurance that the report-

ing of these conditions will bring about

prompt and decisive action.

A printing press is in its best condition the

day it is installed on the press manufacturer’s

floor and tested. From that day on, all further

operation of the press tends to deteriorate

the equipment. Therefore, to keep the equip-

ment running as specified by the manufac-

turer, it is necessary to install the machinery

correctly and maintain it properly.

AREAS OF PROPER MAINTENANCE

If proper press maintenance were easy,

there would be little need for discussion of

the topic. Unfortunately, maintenance is not

a simple task. There are quite a few prac-

tices that should be carried out on a regular

basis, and in the correct fashion.

Installation

A good maintenance program begins with

installation of the machinery. Poor installa-

tion of the press in a converter’s plant can

seldom be overcome by even the finest

maintenance program. The press should be

installed on a solid, level foundation of suf-

ficient strength to carry the weight of the

press and accessory equipment, as specified

by the press manufacturer.

The press must be installed and assembled

perfectly level. Modern high-speed roll print-

ing equipment should only be installed under

the supervision of a factory-trained techni-

cian. Smaller press equipment should at

least be checked out by the press builder’s

technician before it is placed in operation.

Utilities

Flexographic printing presses require

some or all of the following utilities at press-

side: electric power, gas, cooled or refrigerat-

ed water, an air supply and exhaust ducts,

and compressed-air lines. The lines and

sources of power and other services must

have sufficient capacity as specified by the

press manufacturer. Electrical and gas equip-

ment must comply with local safety ordi-

nances and the underwriter’s requirements.

Most press suppliers will furnish a detailed

floor plan of their equipment showing where

the sources of supply must be located. It is

best to have these items taken care of in

advance of the actual press installation in

order to reduce installation time. A pre-

installation survey and program will ensure

that the installation is “clean” and not a series

of uncoordinated supply sources, which may

impede the efficiency of the press during

operation.

Lubrication

Lubrication is an essential element of

maintenance if maximum performance and

life is to be realized from any bearing. In a

correctly operating bearing, a thin film of

lubricant separates the rotating member

from the stationary member. This film should

PRESSES AND PRESS EQUIPMENT 147

be of sufficient thickness to prevent contact

of the metal surfaces. Contact of the metal

surfaces will result in overheating, wear,

scoring and possible seizure. Providing the

wear-preventive film is a primary function of

the lubricant. Lubricants also provide:

• protection from corrosion;

• dissipation of heat;

• exclusion of contaminates; and

• the flushing away of wear products.

Lubricants are generally recommended by

the bearing manufacturer. These recommen-

dations should be strictly followed for peak

performance and maximum bearing life.

Lubricants are classified as:

• greases;

• oils;

• sythentic lubricants; or

• dry lubricants.

Greases. Grease is a combination of petrole-

um oil and a suitable thickener. Thickeners

can range from 3% to 30% of the composition,

or more. Grease is critical to bearing perfor-

mance. It must be properly selected to fit the

application requirements; it must be utilized

in a properly developed maintenance pro-

gram to accomplish the expected perfor-

mance of any particular mechanical system.

Oils. This fluid lubricant is generally more

versatile than grease and suitable for severe

applications involving extreme speeds and

elevated temperatures.

Synthetic Lubricants. Synthetic lubricants

usually permit a broader operating tempera-

ture range and provide good lubrication at

high or low temperatures, beyond the limits

of petroleum lubricants. Most commercial

applications of synthetic lubricants are asso-

ciated with extreme temperature conditions.

Synthetic lubricants are extremely expen-

sive, with costs ranging from double to over

100 times that of petroleum lubricants.

Dry Lubricants. Dry lubricants have been used

for many years in either powder or colloidal

suspension form. Dry lubricants are com-

monly used in applications involving high

temperatures and extremely slow speeds.

Lubrication: An Overview

The three major factors that determine

suitability of a lubricant for a particular appli-

cation are the rotational speed of the bearing,

the load it must support and the temperature

at which it operates. In most instances, a

standard petroleum lubricant will suffice.

However, under conditions in which any of

the three three factors are extreme in their

requirements, petroleum with special addi-

tives or a synthetic are available.

PM Lubrication. Preventive maintenance pro-

grams are considered by some as “oiling

campaigns.” It is true that proper lubrication

of rotating components is an absolute neces-

sity for proper maintenance, but it is not the

only function of a preventive maintenance

program. However, no discussion of preven-

tive maintenance would be complete with-

out discussing the lubrication procedures

for most presses.

Generally required are three basic types of

lubricants: oil, grease and gear grease. Press

manufacturers furnish a lubricating chart

with their equipment, specifying the type and

grade of lubricants to be used. It is important

that no deviation be made from these specifi-

cations, since the suppliers of lubricants

have done much in the way of specialization

in recent years. Every reliable press builder

works closely with one or more oil compa-

nies to determine the most efficient lubri-

cants for individual press components.

To ensure systematic lubrication, either a

separate lubrication chart or one that is

included in the general maintenance check-

list should be used. A simple method to

ensure correct lubrication is to color code

the various lubrication points in accordance

with the type of lubricant that is to be used.

For instance, color code red for oil, blue for

grease, etc.

148 FLEXOGRAPHY: PRINCIPLES & PRACTICES

Anti-friction or Rolling Bearings. In general,

ball or roller bearings must be greased,

never oiled, since oil will not cling to the

balls or rollers and give adequate lubrica-

tion. However, some ball bearings on guide

rolls are specifically designed to run with a

fine silicone-type oil lubricant. In this case,

the bearing retainer seals will have been

removed to allow the oil access to the bear-

ing. It is especially important that this type

of bearing be oiled with the proper lubricant

on a regular basis to ensure that it is not con-

taminated with dirt or grease, which will

impair its efficiency and life.

Other bearings should be greased at least

once a week. Special attention should be paid

to any bearings in the vicinity of the ink foun-

tains, not only to ensure that they are proper-

ly lubricated and full of grease, but also to

ensure that they have not become contami-

nated with spilled ink, dust or dirt. Keeping a

supply of spare bearings for anilox and rub-

ber fountain roll shafts is a good practice.

Sleeve Bushings. Bushings require daily care

and should always be oiled with the grade of

oil specified. They should not be greased,

since grease is not free-flowing enough to

properly distribute itself in the bushings or

sliding bearing. Bushings should be oiled at

the beginning of each work shift and again

after approximately four hours of running

time. If the bushings are automatically lubri-

cated by pre-regulated oiling, care should be

taken to ensure that the master oiling system

is functioning and that it has a sufficient sup-

ply of oil to operate during the pressrun.

It is a good practice to keep at least one set

of spare plate-cylinder bushings or bearings

on hand. These bushings should be replaced

as soon as they show any sign of excessive

wear or play.

One-shot Oilers. Many presses have been

equipped with one-shot oiling systems.

These systems will lubricate all, or a major

part, of the bushings and sliding bearings on

the press by manual or automatic operation

of one or more of the oil pumps on the press.

A one-shot oiling system greatly simplifies

proper periodic lubrication, but it is not an

automatic guarantee that all lubricating

points attached to this system will actually

be oiled. In other words, all lubricating

points incorporated in the one-shot oiling

system should be periodically inspected to

be sure that they are actually receiving oil

and that the system has not become clogged

or inoperative in some sections.

Because of the problems inherent in one-

shot oiling systems and the fact that they

tend to over-oil some areas of the press,

there has been a trend back to the manual

oiling system. Here again, it is necessary that

a proper periodic maintenance program be

set up so that each point on the press that

must be oiled is carefully inspected and

oiled at periodic intervals.

Open Gears. Open gears are usually lubricated

with gear grease applied either from a brush

or paddle and should be greased at least once

every four weeks. Special attention should be

paid to the gears on or in the vicinity of the

printing stations. These gears have a tenden-

cy to collect ink between the teeth, which

may not only cause premature wear or break-

age, but will, in the interim, prevent them

from running on their true pitch line.

Closed Gear Boxes. Beveled or spiral gears

should be properly enclosed in gear boxes,

as the centrifugal forces on these gears are

such that they will quickly rid themselves of

even heavy gear lubricants. All gearboxes

need only be kept filled to the prescribed

level with the specified oil or grease to

ensure continuous lubrication. Oil level on

these gear boxes should be checked on a

daily basis and generally should be drained

completely every three to four months and

refilled with fresh oil or grease.

Brakes and Clutches

In addition to normal oiling and greasing

maintenance, inspection of other compo-

nents on the press is required. On presses

equipped with manual or automatic flying-

splice unwinds, prescribed maintenance

must be taken on the unwind brakes,

whether they be of the simple hand-

adjustable friction type or a more sophisti-

cated electric, pneumatic or electric-particle

brake type. The press manufacturer should

supply manuals for the unwind brakes that

are furnished with the equipment.

In the case of manual or felt friction disc-

type clutches or brakes, it is necessary to

check with the press manufacturer for the

proper procedures to employ.

Hydraulic Cylinders and Lines

Most flexographic presses are equipped

with a hydraulic system that controls plate

cylinder throw-off, variable-speed fountain

drives, nip-roll pressure controls and other

equally important operating systems. Hy-

draulic units are comparatively maintenance

free. However, it is important that the manu-

facturer’s instructions be followed closely

on the initial start-up. The oil tank must be

filled with a proper grade of clean hydraulic

oil, and the system must be properly “bled”

and checked before starting.

If a loss of hydraulic pressure occurs, it is

usually due to leakage in one of the hydrau-

lic oil fittings, the location of which can be

readily spotted. Continual visual inspection

of the hydraulic lines is necessary. Should

leakage develop, new fittings and/or seals

should be installed immediately.

Anilox and Fountain Rolls

Inspection of engraved anilox ink transfer

rolls, as well as the rubber-covered fountain

rolls, can best be delegated to press-operat-

ing personnel, since it can be combined with

the wash-up of these rollers during press

makeready. Press personnel should be in-

structed to promptly report every nick, pit-

ting or peeling of chrome on the anilox roll.

It is possible to repair minor damage at a

comparatively small cost if caught at an

early stage, since these defects on the anilox

roll can cause damage to the rubber fountain

roll and the printing plates. Small imperfec-

tions in the anilox roll will cause spots to be

worn on the rubber roll, appreciably short-

ening its life. Similarly, slight nicks or other

damages to the rubber-covered fountain roll,

if detected promptly, can often be repaired

by regrinding the roll at considerably less

expense than required if the roll is used until

complete recovering becomes necessary.

It is important that the rubber-covered

fountain roll be separated from the engraved

anilox transfer roll whenever the press is

shut down between shifts or for any other

prolonged stoppages. If these rolls are left

squeezed together when not rotating for an

extended period of time, a “flat” will invari-

ably develop on the rubber fountain roll sur-

face. This distortion can only be removed by

regrinding, or in severe cases, by recovering

the roll. Special attention must also be paid

to a thorough and deep cleaning of the

anilox roll at the end of each work day.

Adequate cleaning ensures that ink or sol-

vent residue does not remain in the cells,

where it could attack the chrome plating or

cause cell plugging.

Electric Systems

Electric motors require periodic lubrica-

tion in accordance with each manufacturer’s

instructions, except for those motors that

are equipped with lifetime or sealed bear-

ings. Besides the main drive motor and

numerous auxiliary motors, the electrical

installation on modern high-speed presses

includes relays, switches, eddy-current

clutches, commutator rings and either solid-

state drive control systems or rotating field

AC-to-DC converters.

At the time of press purchase, the press

manufacturer should work with the electric

motor suppliers and drive-component sup-

pliers to prepare a proper preventive main-

PRESSES AND PRESS EQUIPMENT 149

150 FLEXOGRAPHY: PRINCIPLES & PRACTICES

tenance list of spare equipment to be sup-

plied with the press. Drive-system manufac-

turers should supply a preventive mainte-

nance checklist for their equipment and a

listing of the nearest regional office for tech-

nical service should such assistance be nec-

essary. Most modern drive systems have

been designed so that replacement parts

may be easily plugged into the circuit, as it is

recognized that the cost of an electrical engi-

neer’s time to define problem areas and cor-

rect them in the field is expensive.

Dryer

The drying system on most flexographic

printing presses consists of heat-supply units

with electric motor-driven fans for supply

and exhaust air. The drying system should

meet local safety codes, and the press manu-

facturer should supply a clearly defined

schematic for the system. It is especially

important that periodic checks be made of

the drives between the electric motors and

the fans, as well as the motors and compo-

nents in the gas-fired system.

It is also advisable to make sure everything

is properly lubricated. Here again, the press

manufacturer should supply a list of compo-

nents that should be checked routinely to

ensure that the press will not be down for

excessive time due to component failure.

Also, the names and locations of the nearest

service representatives for component parts

of the drying system should be included with

the press maintenance material.

If the dryers are equipped with air filter

banks, they should be inspected often to

ensure that the drying system will operate

properly and that the solvent-laden fumes

are carried out of the pressroom.

Auxiliary Equipment

There are many types of auxiliary equip-

ment supplied both on and separate from a

printing press. This equipment includes web

guides, web scanners, ink pumps, viscosity

controls, impression counters, slitting

attachments, web treatment and other items.

The press manufacturer should supply basic

catalogs that will advise the proper mainte-

nance procedure for each press component.

Proper spare-parts lists should be prepared

on each of these major components, since

they are just as subject to wear and failure as

the printing press itself, and their failure can

interrupt the complete system.

Spare Parts Inventory

The spare parts inventory should receive

careful attention by the converter and the

press manufacturer. If a systematic approach

is taken prior to the press installation, it is

possible to have on hand at the time of start-

up a group of spare parts that can generally

cover 95% of all possible breakdown situa-

tions. The investment in these parts will nor-

mally be such a small fraction of the total

cost of the press, its attendant equipment and

installation, that it should be an integral part

of the initial press purchase. Having the

equipment initially on hand, as well as a good

control system to replace those items that

are used, will, over the years, pay for these

parts many times over.

PRESSMANSHIP AND

EQUIPMENT CARE

In any preventive maintenance program,

the responsibilities of the press operating per-

sonnel are of paramount importance. The

people who live with the equipment are the

first line of defense. Many tasks that come

under the heading of maintenance can be

best carried out on a day-to-day basis by

press-operating personnel. First and foremost

is keeping and maintaining a clean press.

Timely Clean-up

It is not easy to keep a flexographic press

spotless, especially if there is not time set

aside each week for a thorough press clean-

ing. It is, however, easier to wipe away spilled

ink when it is fresh than when it becomes

hardened or accumulated to the point where

removal is a major job. It is easier to empty

drip pans when they are half full than wait

until they are overflowing or filled to the top

when they cannot possibly be removed with-

out spilling. It is easier to wipe small amounts

of excess oil off a press than to wait until an

entire press frame as well as the floor around

the press, becomes covered with an oil film.

Any available time when the press is not run-

ning, or during wash-up, can be profitably

used to take care of such minor cleaning jobs.

Cleaning such routine items will remain minor

as long as it is done on a routine basis.

Not only must the printing press be kept

clean, but the area around the press also must

be kept neat and orderly for an efficient oper-

ation. Floors should be kept clean and proper

containers supplied to hold such items as

rags and waste paper. No unnecessary ink

pails or loose tools should be scattered about

the press area. An orderly work area not only

enables personnel to be more efficient and

craftsman-like, but also eliminates many of

the hazards that might otherwise endanger

the safety of the operating personnel.

The press operator should not create

unnecessary maintenance problems by oper-

ating the equipment improperly, such as by

standing on cross-adjustment shafts and

other items that are not normally designed to

carry an operator’s weight. The maintenance

department should provide proper plat-

forms, ladders and/or steps to allow proper

access to the press. These access areas cre-

ate a neater area and a safer workplace.

Handling Care

Careful handling of parts that are continual-

ly mounted into or removed from the press

during normal operating procedures is a

necessity. Plate cylinders, ink pans and covers

are precision items and require and deserve

care. Plate cylinders that are manufactured

with very close tolerances and that are quite

expensive can perform properly only if their

original tolerances are maintained. Rough

handling of these items can reduce their effec-

tiveness. Pans or covers that become dented

should be repaired immediately, since they

will be harder to clean up and may not fit neat-

ly with the color stations, reducing their effec-

tiveness and requiring longer setup times.

The Press Operator’s Opportunity

At the end of any operating shift or during

makeready, be sure that all fountain rolls are

backed off and properly cleaned. When plac-

ing the press back into adjustment, make

sure that all the components are functioning

and that force is not required to make the

press settings. The parts of the adjustment

system are designed and precision-made to

close tolerances and should operate freely

and smoothly. If they do not operate in this

fashion, then a careful inspection of the

color stations must be made to determine

what is causing the problem so that it may

be properly repaired.

The press operator is the first person to

see signs of the press performance deterior-

ating. The operator’s judgment alone will

often lead to preventive maintenance

beyond the scheduled maintenance on sec-

tions or parts of the press that are just begin-

ning to fail. Press operators who are “tuned

in” to the press not only keep the press oper-

ating at higher efficiency, but make the

pressroom a more pleasant place to work

and a safer operation.

PRESSES AND PRESS EQUIPMENT 151

PRESSES AND PRESS EQUIPMENT 153

Appendix A – Diametric Pitches

20 2.500 7.854

21 2.625 8.247

22 2.750 8.639

23 2.875 9.032

24 3.000 9.425

25 3.125 9.817

26 3.250 10.210

27 3.375 10.603

28 3.500 10.996

29 3.625 11.388

30 3.750 11.781

31 3.875 12.174

32 4.000 12.566

33 4.125 12.959

34 4.250 13.352

35 4.375 13.744

36 4.500 14.137

37 4.625 14.530

38 4.750 14.923

39 4.875 15.315

40 5.000 15.708

41 5.125 16.101

42 5.250 16.493

43 5.375 16.886

44 5.500 17.279

45 5.625 17.671

46 5.750 18.064

47 5.875 18.457

48 6.000 18.850

49 6.125 19.242

50 6.250 19.635

51 6.375 20.028

52 6.500 20.420

53 6.625 20.813

54 6.750 21.206

55 6.875 21.598

56 7.000 21.991

57 7.125 22.384

58 7.250 22.777

59 7.375 23.169

60 7.500 23.562

61 7.625 23.955

62 7.750 24.347

63 7.875 24.740

64 8.000 25.133

65 8.125 25.525

66 8.250 25.918

67 8.375 26.311

68 8.500 26.704

69 8.625 27.096

70 8.750 27.489

71 8.875 27.882

72 9.000 28.274

73 9.125 28.667

74 9.250 29.060

75 9.375 29.452

76 9.500 29.845

77 9.625 30.238

78 9.750 30.631

79 9.875 31.023

80 10.000 31.416

81 10.125 31.809

82 10.250 32.201

83 10.375 32.594

84 10.500 32.987

85 10.625 33.379

86 10.750 33.772

87 10.875 34.165

88 11.000 34.558

89 11.125 34.950

90 11.250 35.343

91 11.375 35.736

92 11.500 36.128

93 11.625 36.521

94 11.750 36.914

95 11.875 37.306

96 12.000 37.699

97 12.125 38.092

98 12.250 38.485

99 12.375 38.877

100 12.500 39.270

NO. OF TEETH PRINTING/PITCH

IN GEAR DIAMETER (IN) REPEAT (IN)

NO. OF TEETH PRINTING/PITCH

IN GEAR DIAMETER (IN) REPEAT (IN)

DIAMETRIC PITCH 8