Harley Davidson 1999-2005 Harley Dyna Models. Repair Manual — page 1

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4

CHAPTER ONE

SERIAL NUMBERS

1

Serial numbers are stamped on various locations

on the frame, engine, transmission and carburetor.

Record these numbers in the Quick Reference Data

section in the front of the book. Have these numbers

available when ordering parts.

The frame serial number (Figure 1) is stamped on

the right side of the frame down tube.

The VIN number label (Figure 2) is located just

below the frame number on the right side frame

down tube.

Engine serial number is stamped on a pad on the

left side of the crankcase (Figure 3), as well as the

right side of the crankcase (Figure 4).

2

The transmission serial number (Figure 5) is

stamped on a pad on the right side of the transmis-

sion case next to the side door.

The carburetor serial number (Figure 6) is lo-

cated on the side of the carburetor body next to the

accelerator pump linkage.

Table 1 lists model designation.

FASTENERS

Proper fastener selection and installation is im-

portant to ensure that the vehicle operates as de-

3

signed and can be serviced efficiently. The choice of

original equipment fasteners is not arrived at by

chance. Make sure that replacement fasteners meet

all the same requirements as the originals.

Threaded Fasteners

Threaded fasteners secure most of the compo-

nents on the vehicle. Most are tightened by turning

them clockwise (right-hand threads). If the normal

rotation of the component being tightened would

loosen the fastener, it may have left-hand threads. If

a left-hand threaded fastener is used, it is noted in

4

the text.

Two dimensions are required to match the threads

of the fastener: the number of threads in a given dis-

tance and the outside diameter of the threads.

Two systems are currently used to specify

threaded fastener dimensions: the U.S. Standard

system and the metric system (Figure 7). Pay par-

ticular attention when working with unidentified

fasteners; mismatching thread types can damage

threads.

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GENERAL INFORMATION

5

5

8

1

T

-9.8

D

L

Grade marking

NOTE

6

To ensure that the fastener threads are

not mismatched or cross-threaded,

start all fasteners by hand. If a fas-

tener is hard to start or turn, deter-

mine the cause before tightening with

a wrench.

The length (L, Figure 8), diameter (D) and dis-

tance between thread crests (pitch) (T) classify met-

ric screws and bolts. A typical bolt may be

identified by the numbers, 8—1.25 × 130. This indi-

cates the bolt has diameter of 8 mm, the distance be-

tween thread crests is 1.25 mm and the length is 130

mm. Always measure bolt length as shown in Fig-

7

ure 8 to avoid purchasing replacements of the

wrong length.

The numbers located on the top of the fastener

(Figure 8) indicate the strength of metric screws

and bolts. The higher the number, the stronger the

fastener is. Unnumbered fasteners are the weakest.

Many screws, bolts and studs are combined with

American

Metric

nuts to secure particular components. To indicate

the size of a nut, manufacturers specify the internal

diameter and the thread pitch.

The measurement across two flats on a nut or bolt

indicates the wrench size.

60°

60°

WARNING

Do not install fasteners with a

strength classification lower than

what was originally installed by the

manufacturer. Doing so may cause

equipment failure and/or damage.

Torque Specifications

The materials used in the manufacture of the ve-

hicle may be subjected to uneven stresses if the fas-

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6

CHAPTER ONE

teners of the various subassemblies are not installed

and tightened correctly. Fasteners that are improp-

9

erly installed or work loose can cause extensive

damage. It is essential to use an accurate torque

wrench, described in this chapter, with the torque

specifications in this manual.

Specifications for torque are provided in New-

ton-meters

(N•m), foot-pounds

(ft.-lb.) and

Correct

inch-pounds (in.-lb.). Refer to Table 6 for general

installation of

cotter pin

torque specifications. To use Table 6, first deter-

mine the size of the fastener as described in Fas-

teners in this chapter. Torque specifications for

specific components are at the end of the appropri-

ate chapters. Torque wrenches are covered in the

Basic Tools section.

Self-Locking Fasteners

Several types of bolts, screws and nuts incorpo-

rate a system that creates interference between the

two fasteners. Interference is achieved in various

ways. The most common type is the nylon insert nut

and a dry adhesive coating on the threads of a bolt.

10

Self-locking fasteners offer greater holding

strength than standard fasteners, which improves

their resistance to vibration. Most self-locking fas-

teners cannot be reused. The materials used to form

the lock become distorted after the initial installa-

tion and removal. It is a good practice to discard and

Internal snap ring

Plain clip

replace self-locking fasteners after their removal.

Do not replace self-locking fasteners with standard

fasteners.

Washers

There are two basic types of washers: flat wash-

External snap ring

E-ring

ers and lockwashers. Flat washers are simple discs

with a hole to fit a screw or bolt. Lockwashers are

used to prevent a fastener from working loose.

tain applications, such as the rear axle on an ATV or

Washers can be used as spacers and seals, or to help

motorcycle, the fastener must be secured in this

distribute fastener load and to prevent the fastener

way. For these applications, a cotter pin and castel-

from damaging the component.

lated (slotted) nut is used.

As with fasteners, when replacing washers make

To use a cotter pin, first make sure the diameter is

sure the replacement washers are of the same design

correct for the hole in the fastener. After correctly

and quality.

tightening the fastener and aligning the holes, insert

the cotter pin through the hole and bend the ends

over the fastener (Figure 9). Unless instructed to do

Cotter Pins

so, never loosen a torqued fastener to align the

A cotter pin is a split metal pin inserted into a hole

holes. If the holes do not align, tighten the fastener

or slot to prevent a fastener from loosening. In cer-

just enough to achieve alignment.

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GENERAL INFORMATION

7

Two basic types of snap rings are used: machined

11

1

and stamped snap rings. Machined snap rings (Fig-

ure 11) can be installed in either direction, since

both faces have sharp edges. Stamped snap rings

(Figure 12) are manufactured with a sharp edge and

a round edge. When installing a stamped snap ring

Full

in a thrust application, install the sharp edge facing

Direction

support

away from the part producing the thrust.

of thrust

areas

E-clips and circlips are used when it is not practi-

cal to use a snap ring. Remove E-clips with a flat

blade screwdriver by prying between the shaft and

E-clip. To install an E-clip, center it over the shaft

groove and push or tap it into place.

Observe the following when installing snap rings:

1. Remove and install snap rings with snap ring pli-

ers. See Snap Ring Pliers in this chapter.

2. In some applications, it may be necessary to re-

place snap rings after removing them.

12

3. Compress or expand snap rings only enough to

install them. If overly expanded, they lose their re-

taining ability.

4. After installing a snap ring, make sure it seats

completely.

Rounded edges

5. Wear eye protection when removing and install-

Sharp edges

ing snap rings.

SHOP SUPPLIES

Lubricants and Fluids

Direction of thrust

Periodic lubrication helps ensure a long service

life for any type of equipment. Using the correct

type of lubricant is as important as performing the

lubrication service, although in an emergency the

Cotter pins are available in various diameters and

wrong type is better than none. The following sec-

lengths.

Measure length from the bottom of the

tion describes the types of lubricants most often re-

head to the tip of the shortest pin.

quired. Make sure to follow the manufacturer’s

recommendations for lubricant types.

Snap rings and E-clips

Engine oils

Snap rings (Figure 10) are circular-shaped metal

retaining clips. They are required to secure parts

Engine oil is classified by two standards: the

and gears in place on parts such as shafts, pins or

American Petroleum Institute (API) service classi-

rods. External type snap rings are used to retain

fication and the Society of Automotive Engineers

items on shafts. Internal type snap rings secure parts

(SAE) viscosity rating. This information is on the

within housing bores. In some applications, in addi-

oil container label. Two letters indicate the API ser-

tion to securing the component(s), snap rings of

vice classification. The number or sequence of

varying thickness also determine endplay. These are

numbers and letter (10W-40 for example) is the oil’s

usually called selective snap rings.

viscosity rating. The API service classification and

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GENERAL INFORMATION

9

moval process and prevent damage to the mating

13

1

surface that may be caused by using a scraping tool.

Most of these types of products are very caustic.

Follow the gasket remover manufacturer’s instruc-

tions for use.

Threadlocking Compound

A threadlocking compound is a fluid applied to

the threads of fasteners. After tightening the fas-

tener, the fluid dries and becomes a solid filler be-

tween the threads. This makes it difficult for the

fastener to work loose from vibration, or heat ex-

Use extreme care when choosing a sealant different

pansion and contraction. Some threadlocking com-

from the type originally recommended. Choose

pounds also provide a seal against fluid leakage.

sealants based on their resistance to heat, various

Before applying threadlocking compound, re-

fluids and their sealing capabilities.

move any old compound from both thread areas and

One of the most common sealants is RTV, or

clean them with aerosol parts cleaner. Use the com-

room temperature vulcanizing sealant. This sealant

pound sparingly. Excess fluid can run into adjoining

cures at room temperature over a specific time pe-

parts.

riod. This allows the repositioning of components

Threadlocking compounds are available in differ-

without damaging gaskets.

ent strengths. Follow the particular manufacturer’s

Moisture in the air causes the RTV sealant to

recommendations regarding compound selection.

cure. Always install the tube cap as soon as possible

Two manufacturers of threadlocking compound are

after applying RTV sealant. RTV sealant has a lim-

ThreeBond and Loctite. They both offer a wide

ited shelf life and will not cure properly if the shelf

range of compounds for various strength, tempera-

life has expired. Keep partial tubes sealed and dis-

ture and repair applications.

card them if they have surpassed the expiration

date.

BASIC TOOLS

Applying RTV sealant

Most of the procedures in this manual can be car-

ried out with simple hand tools and test equipment

Clean all old gasket residue from the mating sur-

familiar to the home mechanic. Always use the cor-

faces. Remove all gasket material from blind

rect tools for the job at hand. Keep tools organized

threaded holes; it can cause inaccurate bolt torque.

and clean. Store them in a tool chest with related

Spray the mating surfaces with aerosol parts cleaner

tools organized together.

and then wipe with a lint-free cloth. The area must

Quality tools are essential. The best are con-

be clean for the sealant to adhere.

structed of high-strength alloy steel. These tools are

Apply RTV sealant in a continuous bead 2-3 mm

light, easy to use and resistant to wear. Their work-

(0.08-0.12 in.) thick. Circle all the fastener holes

ing surface is devoid of sharp edges and the tool is

unless otherwise specified. Do not allow any seal-

carefully polished. They have an easy-to-clean fin-

ant to enter these holes. Assemble and tighten the

ish and are comfortable to use. Quality tools are a

fasteners to the specified torque within the time

good investment.

frame recommended by the RTV sealant manufac-

When purchasing tools to perform the procedures

turer.

covered in this manual, consider the tools’ potential

frequency of use. If a tool kit is just now being

Gasket Remover

started, consider purchasing a basic tool set (Figure

13) from a large tool supplier. These sets are avail-

Aerosol gasket remover can help remove stub-

able in many tool combinations and offer substan-

born gaskets. This product can speed up the re-

tial savings when compared to individually

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10

CHAPTER ONE

purchased tools. As work experience grows and

tasks become more complicated, specialized tools

14

can be added.

Screwdrivers

Screwdrivers of various lengths and types are

mandatory for the simplest tool kit. The two basic

types are the slotted tip (flat blade) and the Phillips

tip. These are available in sets that often include an

assortment of tip sizes and shaft lengths.

As with all tools, use a screwdriver designed for

the job. Make sure the size of the tip conforms to the

15

size and shape of the fastener. Use them only for

driving screws. Never use a screwdriver for prying

or chiseling metal. Repair or replace worn or dam-

aged screwdrivers. A worn tip may damage the fas-

tener, making it difficult to remove.

Wrenches

Open-end, box-end and combination wrenches

(Figure 14) are available in various types and sizes.

The number stamped on the wrench refers to the

16

distance between the work areas. This size must

match the size of the fastener head.

The box-end wrench is an excellent tool because

it grips the fastener on all sides. This reduces the

chance of the tool slipping. The box-end wrench is

designed with either a 6- or 12-point opening. For

stubborn or damaged fasteners, the 6-point provides

superior holding ability by contacting the fastener

across a wider area at all six edges. For general use,

the 12-point works well. It allows the wrench to be

removed and reinstalled without moving the handle

Adjustable Wrenches

over such a wide arc.

An open-end wrench is fast and works best in ar-

An adjustable wrench or Crescent wrench (Fig-

eas with limited overhead access. It contacts the fas-

ure 15) can fit nearly any nut or bolt head that has

tener at only two points, and is subject to slipping

clear access around its entire perimeter. Adjustable

under heavy force, or if the tool or fastener is worn.

wrenches are best used as a backup wrench to keep

A box-end wrench is preferred in most instances,

a large nut or bolt from turning while the other end

especially when breaking loose and applying the

is being loosened or tightened with a box-end or

final tightness to a fastener.

socket wrench.

The combination wrench has a box end on one

Adjustable wrenches contact the fastener at only

end and an open end on the other. This combination

two points, making them more likely to slip off the

makes it a very convenient tool.

fastener. The fact that one jaw is adjustable and may

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GENERAL INFORMATION

11

the socket is the size of the work area and must

17

match the fastener head.

1

As with wrenches, a 6-point socket provides su-

perior holding ability, while a 12-point socket needs

to be moved only half as far to reposition it on the

fastener.

Sockets are designated for either hand or impact

use. Impact sockets are made of thicker material for

more durability. Compare the size and wall thick-

ness of a 19-mm hand socket (A, Figure 18) and the

19-mm impact socket (B). Use impact sockets when

using an impact driver or air tools. Use hand sockets

with hand-driven attachments.

18

WARNING

Do not use hand sockets with air or

impact tools, as they may shatter and

cause injury. Always wear eye protec-

tion when using impact or air tools.

Various handles are available for sockets. The

speed handle is used for fast operation. Flexible

ratchet heads in varying lengths allow the socket to

be turned with varying force, and at odd angles. Ex-

tension bars allow the socket setup to reach difficult

areas. The ratchet is the most versatile. It allows the

user to install or remove the nut without removing

19

the socket.

Sockets combined with any number of drivers

make them undoubtedly the fastest, safest and most

convenient tool for fastener removal and installa-

tion.

Impact Driver

An impact driver provides extra force for remov-

ing fasteners, by converting the impact of a hammer

into a turning motion. This makes it possible to re-

loosen only aggravates this shortcoming. Make cer-

move stubborn fasteners without damaging them.

tain that the solid jaw is the one transmitting the

Impact drivers and interchangeable bits (Figure 19)

force.

are available from most tool suppliers. When using

a socket with an impact driver make sure the socket

is designed for impact use. Refer to Socket

Socket Wrenches, Ratchets and Handles

Wrenches, Ratchets and Handles in this section.

Sockets that attach to a ratchet handle (Figure 16)

WARNING

are available with

6-point

(A, Figure

17) or

Do not use hand sockets with air or

12-point (B) openings and different drive sizes. The

impact tools as they may shatter and

drive size indicates the size of the square hole that

cause injury. Always wear eye protec-

accepts the ratchet handle. The number stamped on

tion when using impact or air tools.

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12

CHAPTER ONE

Allen Wrenches

20

Allen or setscrew wrenches (Figure 20) are used

on fasteners with hexagonal recesses in the fastener

head. These wrenches are available in L-shaped bar,

socket and T-handle types. A metric set is required

when working on most vehicles. Allen bolts are

sometimes called socket bolts.

Torque Wrenches

A torque wrench is used with a socket, torque

adapter or similar extension to tighten a fastener

o a measured torque. Torque wrenches come in sev-

21

eral drive sizes (1/4, 3/8, 1/2 and 3/4) and have vari-

ous methods of reading the torque value. The drive

size indicates the size of the square drive that ac-

cepts the socket, adapter or extension. Common

methods of reading the torque value are the deflect-

ing beam, the dial indicator and the audible click

(Figure 21).

When choosing a torque wrench, consider the

torque range, drive size and accuracy. The torque

specifications in this manual provide an indication

of the range required.

A torque wrench is a precision tool that must be

properly cared for to remain accurate. Store torque

22

wrenches in cases or separate padded drawers

within a toolbox. Follow the manufacturer’s in-

structions for their care and calibration.

Torque Adapters

Torque adapters or extensions extend or reduce

the reach of a torque wrench. The torque adapter

shown in Figure 22 is used to tighten a fastener that

cannot be reached due to the size of the torque

wrench head, drive, and socket. If a torque adapter

changes the effective lever length (Figure 23), the

L+A=E

torque reading on the wrench will not equal the ac-

TW is the torque setting or dial reading on the

tual torque applied to the fastener. It is necessary to

wrench.

recalibrate the torque setting on the wrench to com-

TA is the

torque

specification and the

actual

pensate for the change of lever length. When a

amount of torque that will be applied to the fastener.

torque adapter is used at a right angle to the drive

head, calibration is not required, since the effective

A is the amount that the adapter increases (or in

length has not changed.

some cases reduces) the effective lever length as

measured along the centerline of the torque wrench

To recalculate a torque reading when using a

(Figure 23).

torque adapter, use the following formula, and refer

to Figure 23.

L is the lever length of the wrench as measured

TW = TA ×L

from the center of the drive to the center of the grip.

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GENERAL INFORMATION

13

HOW TO MEASURE TORQUE WRENCH EFFECTIVE LENGTH

1

23

L

A

L

A

L+A= Effective length

L

L= Effective length

L

No calculation needed

24

25

The effective length is the sum of L and A (Fig-

When using a beam-type wrench, tighten the fas-

ure 23).

tener until the pointer aligns with 16.5 ft.-lb. In this

Example:

example, although the torque wrench is preset to

TA = 20 ft.-lb.

16.5 ft.-lb., the actual torque is 20 ft.-lb.

A= 3 in.

L = 14 in.

Pliers

E = 17 in.

TW = 20×14 = 280 = 16.5 ft. Lb.

Pliers come in a wide range of types and sizes.

14 +3 = 17

Pliers are useful for holding, cutting, bending, and

In this example, the torque wrench would be set

crimping. Do not use them to turn fasteners. Figure

to the recalculated torque value (TW = 16.5 ft.-lb.) .

24 and Figure 25 show several types of useful pli-

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14

CHAPTER ONE

26

27

ers. Each design has a specialized function.

Slip-joint pliers are general-purpose pliers used for

28

gripping and bending. Diagonal cutting pliers are

needed to cut wire and can be used to remove cotter

pins. Needlenose pliers are used to hold or bend

small objects. Locking pliers (Figure 25), some-

times called Vise-grips, are used to hold objects

very tightly. They have many uses, ranging from

holding two parts together to gripping the end of a

broken stud. Use caution when using locking pliers,

as the sharp jaws will damage the objects they hold.

Snap Ring Pliers

when a metal object must be struck without damag-

ing it. Never use a metal-faced hammer on engine

Snap ring pliers are specialized pliers with tips

and suspension components, as damage will occur

that fit into the ends of snap rings to remove and in-

in most cases.

stall them.

Snap ring pliers are available with a fixed action

Always wear eye protection when using ham-

(either internal or external) or convertible (one

mers. Make sure the hammer face is in good condi-

tool works on both internal and external snap

tion and the handle is not cracked. Select the correct

rings). They may have fixed tips or interchange-

hammer for the job and make sure to strike the ob-

able ones of various sizes and angles. For general

ject squarely. Do not use the handle or the side of the

use, select a convertible type pliers with inter-

hammer to strike an object.

changeable tips.

PRECISION MEASURING TOOLS

WARNING

Snap rings can slip and fly off when

removing and installing them. Also,

The ability to accurately measure components is

the snap ring pliers tips may break.

essential to successfully rebuild an engine. Equip-

Always wear eye protection when us-

ment is manufactured to close tolerances, and ob-

ing snap ring pliers.

taining consistently accurate measurements is

essential to determining which components require

replacement or further service.

Hammers

Each type of measuring instrument is designed to

Various types of hammers (Figure 26) are avail-

measure a dimension with a certain degree of accu-

able to fit a number of applications. A ball-peen

racy and within a certain range. When selecting the

hammer is used to strike another tool, such as a

measuring tool, make sure it is applicable to the

punch or chisel. Soft-faced hammers are required

task.

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GENERAL INFORMATION

15

10.00 mm

29

0.50 mm

1

10.55 mm

Fixed scale

0.400 mm

0.013 mm

Moveable scaless

0.413 mm

As with all tools, measuring tools provide the best

A common use for a feeler gauge is to measure

results if cared for properly. Improper use can dam-

valve clearance. Wire (round) type gauges are used

age the tool and result in inaccurate results. If any

to measure spark plug gap.

measurement is questionable, verify the measure-

ment using another tool. A standard gauge is usually

Calipers

provided with measuring tools to check accuracy

and calibrate the tool if necessary.

Calipers (Figure 28) are excellent tools for ob-

Precision measurements can vary according to

taining inside, outside and depth measurements. Al-

the experience of the person performing the proce-

though not as precise as a micrometer, they allow

dure. Accurate results are only possible if the me-

reasonable precision, typically to within 0.05 mm

chanic possesses a feel for using the tool.

(0.001 in.). Most calipers have a range up to 150

Heavy-handed use of measuring tools will produce

mm (6 in.).

less accurate results. Hold the tool gently by the fin-

Calipers are available in dial, vernier or digital

gertips so the point at which the tool contacts the

versions. Dial calipers have a dial readout that pro-

object is easily felt. This feel for the equipment will

vides convenient reading. Vernier calipers have

produce more accurate measurements and reduce

marked scales that must be compared to determine

the risk of damaging the tool or component. Refer to

the measurement. The digital caliper uses an LCD

the following sections for specific measuring tools.

to show the measurement.

Properly maintain the measuring surfaces of the

caliper. There must not be any dirt or burrs between

Feeler Gauge

the tool and the object being measured. Never force

the caliper closed around an object; close the caliper

The feeler or thickness gauge (Figure 27) is used

around the highest point so it can be removed with a

for measuring the distance between two surfaces.

slight drag. Some calipers require calibration. Al-

A feeler gauge set consists of an assortment of

ways refer to the manufacturer’s instructions when

steel strips of graduated thickness. Each blade is

using a new or unfamiliar caliper.

marked with its thickness. Blades can be of various

To read a vernier caliper refer, to Figure 29. The

lengths and angles for different procedures.

fixed scale is marked in 1 mm increments. Ten indi-

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16

CHAPTER ONE

30

DECIMAL PLACE VALUES*

0.1

Indicates 1/10 (one tenth of an inch

or millimeter)

0.010

Indicates 1/100 (one one-hundreth of

an inch or millimeter)

0.001

Indicates 1/1,000 (one one-thousandth

of an inch or millimeter)

*This chart represents the values of figures placed to the right of the decimal point. Use it when

reading decimals from one-tenth to one one-thousandth of an inch or millimeter. It is not a con-

version chart (for example: 0.001 in. is not equal to 0.001 mm).

vidual lines on the fixed scale equal 1 cm. The

moveable scale is marked in 0.05 mm (hundredth)

31

increments. To obtain a reading, establish the first

number by the location of the 0 line on the movable

scale in relation to the first line to the left on the

fixed scale. In this example, the number is 10 mm.

To determine the next number, note which of the

lines on the movable scale align with a mark on the

fixed scale. A number of lines will seem close, but

only one will align exactly. In this case, 0.50 mm is

the reading to add to the first number. The result of

adding 10 mm and 0.50 mm is a measurement of

10.50 mm.

Reading a Micrometer

Micrometers

When reading a micrometer, numbers are taken

from different scales and added together. The fol-

A micrometer is an instrument designed for linear

lowing sections describe how to read the measure-

measurement using the decimal divisions of the

ments of various types of outside micrometers.

inch or meter (Figure 30). While there are many

For accurate results, properly maintain the mea-

types and styles of micrometers, most of the proce-

suring surfaces of the micrometer. There cannot be

dures in this manual call for an outside micrometer.

any dirt or burrs between the tool and the measured

The outside micrometer is used to measure the out-

object. Never force the micrometer closed around

side diameter of cylindrical forms and the thickness

an object. Close the micrometer around the highest

of materials.

point so it can be removed with a slight drag. Figure

A micrometer’s size indicates the minimum and

32 shows the markings and parts of a standard inch

maximum size of a part that it can measure. The

micrometer. Be familiar with these terms before us-

usual sizes (Figure 31) are 0-1 in. (0-25 mm), 1-2

ing a micrometer in the following sections.

in. (25-50 mm), 2-3 in. (50-75 mm) and 3-4 in.

(75-100 mm).

Micrometers that cover a wider range of measure-

Standard inch micrometer

ments are available. These use a large frame with

interchangeable anvils of various lengths. This type

The standard inch micrometer is accurate to

of micrometer offers a cost savings; however, its

one-thousandth of an inch or 0.001. The sleeve is

overall size may make it less convenient.

marked in 0.025 in. increments. Every fourth sleeve

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GENERAL INFORMATION

17

32

STANDARD INCH MICROMETER

1

Sleeve line

Locknut

Spindle

Thimble marks

Anvil

Thimble

Ratchet

Sleeve

numbers

Frame

33

Thimble

Sleeve

1. Largest number visible on the

sleeve line

0.200 in.

2. Number on sleeve marks visible

between the numbered sleeve mark

and the thimble edge

0.025 in.

3. Thimble mark that aligns with

sleeve line

0.006 in.

Total reading

0.231 in.

mark is numbered 1, 2, 3, 4, 5, 6, 7, 8, 9. These num-

NOTE

If a thimble mark does not align ex-

bers indicate 0.100, 0.200, 0.300, and so on.

actly with the sleeve line, estimate the

The tapered end of the thimble has twenty-five

amount between the lines. For accu-

lines marked around it. Each mark equals 0.001 in.

rate readings in ten-thousandths of an

One complete turn of the thimble will align its zero

inch (0.0001 in.), use a vernier inch

mark with the first mark on the sleeve or 0.025 in.

micrometer.

When reading a standard inch micrometer, per-

form the following steps while referring to Figure

4. Add the readings from Steps 1-3.

33.

1. Read the sleeve and find the largest number visi-

Vernier inch micrometer

ble. Each sleeve number equals 0.100 in.

2. Count the number of lines between the num-

A vernier inch micrometer is accurate to one

bered sleeve mark and the edge of the thimble. Each

ten-thousandth of an inch or 0.0001 in. It has the

sleeve mark equals 0.025 in.

same marking as a standard inch micrometer with

3. Read the thimble mark that aligns with the

an additional vernier scale on the sleeve (Figure

sleeve line. Each thimble mark equals 0.001 in.

34).

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18

CHAPTER ONE

34

Vernier scale

1. Largest number visible on

sleeve line

0.100 in.

Sleeve

Thimble

2. Number of sleeve marks visible

between the numbered sleeve mark

Vernier scale

and the thimble edge

0.050 in.

3. Thimble is between 0.018 and 0.019

in. on the sleeve line

0.018 in.

4. Vernier line coinciding with

thimble line

0.0003 in.

Total reading

0.1683 in.

Sleeve Thimble

35

STANDARD METRIC MICROMETER

Sleeve line

Locknut

Thimble

Spindle

Anvil

Ratchet

Sleeve marks Thimble marks

The vernier scale consists of 11 lines marked 1-9

amount in ten-thousandths of an inch to add to the

with a 0 on each end. These lines run parallel to the

initial reading from Step 1.

thimble lines and represent 0.0001 in. increments.

When reading a vernier inch micrometer, perform

the following steps while referring to Figure 34.

Metric micrometer

1. Read the micrometer in the same way as a stan-

The standard metric micrometer (Figure 35) is

dard micrometer. This is the initial reading.

accurate to one one-hundredth of a millimeter

2. If a thimble mark aligns exactly with the sleeve

(0.01-mm). The sleeve line is graduated in millime-

line, reading the vernier scale is not necessary. If

ter and half millimeter increments. The marks on

they do not align, read the vernier scale in Step 3.

the upper half of the sleeve line equal 1.00 mm. Ev-

3. Determine which vernier scale mark aligns with

ery fifth mark above the sleeve line is identified

one thimble mark. The vernier scale number is the

with a number. The number sequence depends on

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GENERAL INFORMATION

19

36

1

Sleeve Thimble

1. Reading on upper sleeve line

5.00 mm

2. Reading on lower sleeve line

0.50 mm

3. Thimble line coinciding with

sleeve line

0.18 mm

Total reading

5.68 mm

Sleeve

Thimble

the size of the micrometer. A 0-25 mm micrometer,

Metric vernier micrometer

for example, will have sleeve marks numbered 0

A metric vernier micrometer (Figure 37) is accu-

through 25 in 5 mm increments. This numbering se-

rate to two-thousandths of a millimeter (0.002 mm).

quence continues with larger micrometers. On all

It has the same markings as a standard metric mi-

metric micrometers, each mark on the lower half of

crometer with the addition of a vernier scale on the

the sleeve equals 0.50 mm.

sleeve.

The tapered end of the thimble has 50 lines marked

The vernier scale consists of five lines marked 0,

around it. Each mark equals 0.01 mm. One complete

2, 4, 6, and 8. These lines run parallel to the thimble

turn of the thimble aligns its 0 mark with the first line

lines and represent 0.002-mm increments.

on the lower half of the sleeve line or 0.50 mm.

When reading a metric vernier micrometer, per-

When reading a metric micrometer, add the num-

form the following steps and refer to Figure 37.

ber of millimeters and half-millimeters on the

1. Read the micrometer in the same way as a stan-

sleeve line to the number of one one-hundredth mil-

dard metric micrometer. This is the initial reading.

limeters on the thimble. Perform the following steps

2. If a thimble mark aligns exactly with the sleeve

while referring to Figure 36.

line, reading the vernier scale is not necessary. If

1. Read the upper half of the sleeve line and count

they do not align, read the vernier scale in Step 3.

the number of lines visible. Each upper line equals 1

3. Determine which vernier scale mark aligns ex-

mm.

actly with one thimble mark. The vernier scale

2. See if the half-millimeter line is visible on the

number is the amount in two-thousandths of a milli-

lower sleeve line. If so, add 0.50 mm to the reading

meter to add to the initial reading from Step 1.

in Step 1.

3. Read the thimble mark that aligns with the

sleeve line. Each thimble mark equals 0.01 mm.

Micrometer Adjustment

NOTE

Before using a micrometer, check its adjustment

If a thimble mark does not align ex-

as follows.

actly with the sleeve line, estimate the

1. Clean the anvil and spindle faces.

amount between the lines. For accu-

2A. To check a 0-1 in. or 0-25 mm micrometer:

rate readings in two-thousandths of a

a. Turn the thimble until the spindle contacts the

millimeter (0.002 mm), use a metric

anvil. If the micrometer has a ratchet stop, use

vernier micrometer.

it to ensure that the proper amount of pressure

4. Add the readings from Steps 1-3.

is applied.