METRIC CONVERSIONS

1988 Jeep Cherokee

GENERAL INFORMATION

METRIC CONVERSIONS

METRIC CONVERSIONS

Metric conversions are making life more difficult for the mechanic. In addition to doubling the number of tools required, metric-dimensioned nuts and bolts are used alongside English components in many new vehicles. The mechanic has to decide which tool to use, slowing down the job. The tool problem can be solved by trial and error, but some metric conversions aren’t so simple. Converting temperature, lengths or volumes requires a calculator and conversion charts, or else a very nimble mind. Conversion charts are only part of the answer though, because they don’t help you "think" metric, or "visualize" what you are converting. The following examples are intended to help you "see" metric sizes:

LENGTH

Meters are the standard unit of length in the metric system. The smaller units are 10ths (decimeter), 100ths (centimeter), and 1000ths (millimeter) of a meter. These common examples might help you to visualize the metric units:

  1. A meter is slightly longer than a yard (about 40 inches).

  2. An aspirin tablet is about one centimeter across (.4 inches).

  3. A millimeter is about the thickness of a dime.

VOLUME

Cubic meters and centimeters are used to measure volume, just as we normally think of cubic feet and inches. Liquid volume measurements include the liter and milliliter, like the English quarts or ounces.

  1. One teaspoon is about 4 cubic centimeters.

  2. A liter is about one quart.

  3. A liter is about 61 cubic inches.

WEIGHT

The metric weight system is based on the gram, with the most common unit being the kilogram (1000 grams). Our comparable units are ounces and pounds:

  1. A kilogram is about 2.2 pounds.

  2. An ounce is about 2 8 grams.

TORQUE

Torque is somewhat complicated. The term describes the amount of effort exerted to turn something. A chosen unit of weight or force is applied to a lever of standard length. The resulting leverage is called torque. In our standard system, we use the weight of one pound applied to a lever a foot long, resulting in the unit called a footpound. A smaller unit is the inch-pound (the lever is one inch long).

Metric units include the meter kilogram (lever one meter long with a kilogram of weight applied) and the Newton-meter (lever one

meter long with force of one Newton applied). Some conversions are:

  1. A meter kilogram is about 7.2 foot pounds.

  2. A foot pound is about 1.4 Newton-meters.

  3. A centimeter kilogram (cmkg) is equal to .9 inch pounds.

PRESSURE

Pressure is another complicated measurement. Pressure is described as a force or weight applied to a given area. Our common unit is pounds per square inch. Metric units can be expressed in several ways. One is the kilogram per square centimeter (kg/cm) . Another unit of pressure is the Pascal (force of one Newton on an area of one square meter), which equals about 4 ounces on a square yard. Since this is a very small amount of pressure, we usually see the kiloPascal, or kPa (1000 Pascals). Another common automotive term for pressure is the bar (used by German manufacturers) , which equals 10 Pascals. Thoroughly confused? Try the examples below:

  1. Atmospheric pressure at sea level is about 14.7 psi.

  2. Atmospheric pressure at sea level is about 1 bar.

  3. Atmospheric pressure at sea level is about 1 kg/cm .

  4. One pound per square inch is about 7 kPa.

CONVERSION FACTORS

CONVERSION FACTORS



TO CONVERT

TO

MULTIPLY BY

LENGTH



Millimeters (mm)

Inches

.03937

Inches

Millimeters

25.4

Meters (M)

Feet

3.28084

Feet

Meters

.3048

Kilometers(Km)

Miles

.62137

AREA



Square Centimeters (cm)

Square Inches

.155

Square Inches

Square Centimeters

6.45159

VOLUME



Cubic Centimeters

Cubic Inches

.06103

Cubic Inches

Cubic Centimeters

16.38703

Liters

Cubic Inches

61.025

Cubic Inches

Liters

.01639

Liters

Quarts

1.05672

Quarts

Liters

.94633

Liters

Pints

2.11344

Pints

Liters

.47317

Liters

Ounces

33.81497

Ounces

Liters

.02957

WEIGHT



Grams

Ounces

.03527

Ounces

Grams

28.34953

Kilograms

Pounds

2.20462

Pounds

Kilograms

.45359

WORK



Centimeter Kilograms

Inch Pounds

.8676

Pounds/Sq. Inch

Kilograms/Sq.Centimeter

.07031

Bar

Pounds/Sq. Inch

14.504

Pounds/Sq. Inch Atmosphere Pounds/Sq. Inch

Bar Pounds/Sq. Inch Atmosphere

.06895 14.696 .06805

TEMPERATURE Centigrade Degrees Fahrenheit Degrees

Fahrenheit Degrees Centigrade Degrees

(Cx(9)/5)+32 (F-32)x(5)/9

CONVERSION FACTORS (Cont.

INCHES

DECIMALS

mm


1/64 016

1/32 031

3/64 047

1/16 063

5/64 078

3/32 094

7/64 109

1/8 125

9/64 141

5/32 156

11/64 172

3/16 188

13/64 203

7/32 219

15/64 234

1/4 250

17/64 266

9/32 281

19/64 297

5/16 313

21/64 328

11/32 344

23/64 359

3/8 375

25/64 391

13/32 406

27/64 422

7/16 438

29/64 453

15/32 469

31/64 484

1/2 500

33/64 516

17/32 531

35/64 547

9/16 563

37/64 578

19/32 594

39/64 609

5/8 625

41/64 641

21/32 656

43/64 672

11/16 687

45/64 703

23/32 719

47/64 734

3/4 750

49/64 766

.397

.794

1.191

1.588

1.984

2.381

2.778

3.175

3.572

3.969

4.366

4.763

5.159

5.556

5.953

6.350

6.747

7.144

7.541

7.938

8.334

8.731

9.128

9.525

9.992

10.319

10.716

11.113

11.509

11.906

12.303

12.700

13.097

13.494

13.891

14.288

14.684

15.081

15.478

15.875

16.272

16.669

17.066

17.463

17.859

18.256

18.653

19.050

19.447

25/32 781 19.844

51/64 797 20.241

13/16 813 20.638

53/64 828 21.034

27/32 844 21.431

55/64 859 21.828

7/8 875 22.225

57/64 891 22.622

29/32 906 23.019

59/64 922 23.416

15/16 938 23.813

61/64 953 24.209

31/32 969 24.606

63/64 984 25.003

1 1.000 25.400