Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST)

on October 9, 2015.

NATIONAL BUREAU OF STANDARDS REPORT

7344

WATER FAUCET WASHERS

by

R. D. Stiehler, G. G. Richey,

E. A. Koerner and R. W. Young

to

i Navy Bureau of Yards and Docks

Army Engineers

Air Force

<NBS>

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
THE NATIONAL BUREAU OF STANDARDS

Functions and Activities

The functions of the National Bureau of Standards are set forth in the Act of Congress, March 3, 1901, as amended by Congress in Public Law 619, 1950. These include the development and maintenance of the national standards of measurement and the provision of means and methods for making measurements consistent

with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials, devices, and structures; advisory services to government agencies on scientific and technical problems; invention and development of devices to serve special needs of the Government; and the development of standard practices, codes, and specifications. The work includes basic

and applied research, development, engineering, instrumentation, testing, evaluation, calibration services,

and various consultation and information services. Research projects are also performed for other government

agencies when the work relates to and supplements the basic program of the Bureau or when the Bureau's

unique competence is required. The scope of activities is suggested by the listing of divisions and sections on the inside of the back cover.

Publications

The results of the Bureau’s research are published either in the Bureau’s own series of publications or

in the journals of professional and scientific societies. The Bureau itself publishes three periodicals avail- able from the Government Printing Office: The Journal of Research, published in four separate sections,

presents complete scientific and technical papers; the Technical News Bulletin presents summary and pre- liminary reports on work in progress; and Basic Radio Propagation Predictions provides data for determining

the best frequencies to use for radio communications throughout the world. There are also five series of nonperiodical publications: Monographs, Applied Mathematics Series, Handbooks, Miscellaneous Publications,

and Technical Notes. A complete listing of the Bureau’s publications can be found in National Bureau of Standards Circular

460, Publications of the National Bureau of Standards, 1901 to June 1947 (81.25), and the Supplement to National Bureau of Standards Circular 460, July 1947 to June 1957 ($1.50), and Miscellaneous Publication 240,

July 1957 to June 1960 (Includes Titles of Papers Published in Outside Journals 1950 to 1959) (82.25); avail- able from the Superintendent of Documents, Government Printing Office, Washington 25, D. C.
NATIONAL BUREAU OF STANDARDS REPORT

MBS PROJECT MBS REPORT

0705-20-07504 September 29, 1961 7544

WATER FAUCET WASHERS

Final Report

January 1, i960 to June 50, 1961

by

R. D. Stiehler, G. G. Richey,

E. A. Koemer and R. W. Young

to

Navy Bureau of Yards and Docks

Army Engineers

Air Force

IMPORT A NT NOTICE

NATIONAL BUREAU OF STANDARDS REPORTS are usually preliminary or progress accounting document*

intended for use within the Government. Before material In the reports Is formally published It is subjected

to additional evaluation and review. For this reason, the publication, reprinting, reproduction, or open-literature

listing of this Report, either in whole or In part, is not authorized unless permission is obtained in writing from

the Office of the Director, National Bureau of Standards, Washington 25, D. C. Such permission Is not needed,

however, by the Government agency for which the Report has been specifically prepared If that agency wishes

to reproduce additional copies for its own use. <NBS>

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

WATER FAUCET WASHERS

by

R. D. Stiehler, G. G. Richey,

E. A. Koemer and R. W. .Young

Summary

A study of the performance of faucet washers was

undertaken by the National Bureau of Standards in 1959.

For this purpose, a simulated service tester was designed

and constructed. This tester applied a constant closing

torque on the washers and permitted 12 washers to be tested

simultaneously. Laboratory measurements of weight changes

in hot air and water, of, stiffness before and after conditioning, and of compression set were also made on the

washers and the results of these tests were compared with

service performance.

No correlation was noted between the laboratory measure

ments and service performance. It was concluded that in the

light of our present knowledge a simulated service test is

required to evaluate faucet washers. Further studies would

have to be made in order to determine which characteristics

of washers govern performance.

The results of the simulated service tests showed

nylon washers to be outstanding. Field trials of these

washers should be made to determine overall performance in

use. The results also showed that rubber washers satisfactory for both hot and cold water service are available.

However, there was a marked difference in the performance

of the rubber washers tested so that a laboratory service

test is required to ascertain those having the desired

quality.

Introduction

When the National Bureau of Standards agreed to undertake this project in 1959 ^ water faucet washers were being

procured under Military Specification Mil-W-190l6. This

specification required the washers to be made of polychloroprene synthetic rubber (Neoprene) and had requirements for

tensile strength, elongation, hardness and specific gravity.

This specification had two weaknesses : (l ) it was not possibl

to measure tensile strength and elongation on the washers

themselves, and (2) the performance of washers supplied

under this specification varied greatly. The wastage of
2

water and the labor for replacement that result from faulty

or short-lived washers warranted the purchase of the highest

quality washers. Therefore, there was a great incentive to

improve the specification.

This project was established in 1959 to obtain performance data on faucet washers and compare these data with

their physical characteristics. It was initially planned

to use a simulated service tester supplied by the Crest

Manufacturing Co. This tester was received in January i960

and was found to be unsuitable for this project. A survey

was made of testers used by various organizations. None

of the testers reviewed applied a constant closing torque

on the washer throughout the test. Therefore, it was

decided in consultation with the Sponsors of the project

to design and construct a new tester. Work on the tester

was started in the last quarter of Fiscal Year i960.

Design of Tester

The tester as initially designed and constructed is

shown in figure 1. Two things in this design cause

difficulties: (l) the beaded chain fatigues rapidly and

(2) the large clearance in the screw threads and guide

permits misalignment of the valve stem by the closing torque.

In the final design, braided venetian-blind cotton cord

replaces the beaded chain and an outboard bearing prevents

misalignment of the stem by the closing torque. Figure 2

is a schematic diagram of the final design showing two of

the twelve positions.

The design of the tester included twelve valves,

permitting twelve washers 17/52 inch in diameter to be

tested simultaneously. American-Standard valve R-1452

was used since it was designed with replaceable stem,

seat and screw threads and since the inlet and outletwater connections of this valve were separated by about

five inches from the handle. These features facilitated

the design and operation of the tester. The double screw

thread of this valve had a lead of '1/4 inch; that is a

560-degree revolution of the stem raised or lowered the

washer 0.25 inch. The stem was turned through an angle

of about 90 degrees during each opening and closing. The

stems of the valves were actuated by a 1/2 h.p., 120 v,

1750 rev/min AC motor operating through a 40 to 1

reduction gear and connecting links. Thus, there were

about 44 closures per minute.
3

The inlets to the valves were connected to common supply

pipes of hot and cold water. The hot water was maintained

at about 85° C (185° F). The cold water was essentially at

the temperature of the water in the city mains. The outlets

of the valves were connected to pieces of tubing that emptied

into a common 2- inch drain pipe.

As shown in figures 1 and 2, the closing torque was

applied by a dead weight acting on a pulley about 6 inches

in diameter. This design caused the torque to remain

constant from the beginning to the end of the test.

Initially, beaded chain was used to connect the dead weights

and the pulleys. This chain fatigued rapidly. Therefore,

the chain was replaced with textile cords ordinarily used

for Venetian blinds. New cords were used for every test.

Materials

A total of 28 different washer compositions were

received from the following suppliers : American-Standard Plumbing and Heating Division

Crest Manufacturing Company, Inc.

Garlock Packing Company

Good Manufacturing Co., Inc.

Kirkhill, Inc..

Radiator Specialty Company

Wolverine Brass Works

Woodward-Wanger Co.

The following number and types of washers were

included: 3 fiber, 3 sandwich, 11 flat rubber, 7 beveled

rubber, and 3 plastic materials. The rubber washers were

analyzed for type of rubber, and the International Rubber

Hardness of all washers was measured with a micro tester.

The composition and hardness of the washers are given in

Table 1. The hardness of the washers in International

Rubber Hardness Degrees (IRHD) ranged as follows:

Rubber washers 90 to 98

Fiber, sandwich and Teflon washers 99*5 to 99.9

Delrin and nylon washers over 99.9
4

Procedure

In the first test, a study was made of the effect of

torque on performance. Three torques were employed, namely,

6.8, 1 3.6, and 20.4 lb-in. The twelve positions on the

tester were divided into three groups of four positions,

each group having one of the three torques . Four types

of washer were used, one of each type was tested at

torques of 6.8 and 13 . 6 lb-in and four of each type

were tested at a torque of 20.4 lb-in. At this highest

torque, the washers were allocated to the four positions

in accordance with a latin-square statistical design.

In subsequent tests, a torque of 20 lb- in was used

on all positions. Generally, 12 types of washers were

included in a test and 4 runs were made so that a minimum

of 4 washers of each type was included in the test. The

washers were allocated among the 12 positions in accordance with a statistical design.

After installing the washers in the tester, the

angular position of a fixed point on each stem was measured

with a protractor to the nearest degree. Measurements

were made with the stem turned to the closed position

under the full closing torque. The tester was started.

The water pressure was adjusted to about- 10 lb/in2 when

6 valves were opened and about 30 lb/in2 when all valves

were closed. After a prescribed number of closures

(generally every 1000 for the first 5000 closures), the

angular position of the stem was measured in the same

manner as initially. Examination was made for leaks

during these measurements. If the change in angular

position for a washer exceeded 150 degrees, the opening

mechanism for this washer was made inoperative and the

test of the other washers continued until a prescribed

number of closures was completed.

The washers were examined upon removal from the tester.

The washers were also weighed before and after test.

However, the change in weight was not a useful index for

judging performance because of the absorption of water

and extraction of water solubles.
5

Effect of Closing Torque

The effect of the magnitude of the closing torque was

studied using a fiber washer* a sandwich washer* and two

flat rubber washers. As mentioned previously, the following

closing torques were used: 6.8* 1 3.6* and 20.4 lb-in. At

the high closing torque* some of the washers were worn

through completely in less than 60*000 closures. Therefore*

the washers being tested at 20.4 lb-in torque were replaced

at the end of 60*000 closures and four washers of each

type were tested at this torque while only one washer of

each type was tested at each of the lower torques. The

test was discontinued after 400*000 closures* when the

following change in angular position of the stem was noted:

Washer Torque

b.d lb-in 13.6 lb- in 20.4 lb-:

F-3A 53° * 64° * 112°

S-3A 56 * 78 * 112

CR-6A 54 8l * 118

CR-2A 26 * 92 155 +

a/ At 60*000 closures

* Leaks observed during test

The small amount of wear* most of which appeared to

be set during the early part of the test* and the leaking

that occurred indicated that a closing torque of greater

than 13.6 lb- in was required. The results at the high

closing torque are not reliable since the test should

have been stopped before 60*000 closures and insufficient

measurements were made during the early portion of the

test. No leaking was observed at the high torque. Since

a rapid test was desired* no attempt was made to explore

the effect of closing torque between 13.6 and 20.4 lb-in.

A torque of 20 lb-in was chosen for subsequent tests and

the number of closures was limited to 15., 000.

Comparison of Commercial Washers

Two tests were made in which 23 commercial washers

were compared. These washers included the following types:

3 fiber* 3 sandwich* 4 nitrile rubber (3 flat and 1

beveled)* 11 polychloroprene rubber (4 flat* 5 beveled*

1 concave* and 1 special)* and 2 rubber washers (l flat

and 1 beveled) made from a blend of natural rubber and SBR.
6

The results of test are given in Table 2 which gives

the change in angular position of the stem after 1000,

5000, and 15000 closures. A comparison of washers in

this table leads to the following conclusions:

1 . There was a large variation in the performance of

different commercial washers

2. Some rubber washers performed as well as the fiber

and sandwich washers in these tests with very hot

water (85° C, 185° F).

5. The performance of rubber washers was not correlated

with the type of rubber.

4. The beveled washers having the same composition as

flat rubber washers tended to perform better.

5. The sandwich washers had a relatively small change

in angular position of the stem. However, this

change was sufficient in many instances to cut

through the outside layer and leave an annular

ring. This ring separated and clogged the exit

port in several instances.

Effect of Cold and Hot Water

Twelve of the washers that performed best in tests 2

and 5 were used in a test to study the effect of cold and

hot water. This test was made during December i960 and

January 1961 when the temperature of the cold water was

4° to 5° 0 (59° to 4l

f> F). In a preliminary test, it was

found that the main change in angular position of the stem

occurred during the early portion of the test. Between

15.5-000 and 100,000 closures in cold water the angular

position changed only 12 degrees on the average. Therefore, a comparison was made of 15*000 closures in cold

water, followed by 15>000 closures in hot water.

The results are given in Table 5. They indicate that

the rubber washers perform better in cold water and the

fiber and sandwich washers perform better in hot water.

The total angular change for 50,000 closures (15*000 at

5

C C and 15,000 at 85° C) tends to be less than for 15*000

closures at 85° 0 listed in Table 2. This effect may be

due to water absorption at 5° C that reduces the severity

of test at 85° C. This behavior warrants further study.

However, the relative performance of the washers is

comparable in Tables 2 and 5* within the precision of test.
7

Performance of Plastic Washers

Three types of plastic washers were obtained; namely,

Delrin, Nylon, and Teflon. These washers were compared

with the three flat rubber washers; NBR-1A, NBR-2A, and

CR-1A. The test consisted of 15,000 closures at 10° to

11° C (50° to 52° F) and 15*000 closures at 85° C. Six

washers of each type were tested instead of four as in

previous tests.

The results are given in Table 4. The angular changes

for the plastic washers are much less than those for the

rubber washers both at 10° and 85 ° C. Particularly striking

is the low angular change for the Nylon washer, N-1A.

The appearance of this washer at the end of the test was

excellent

„

Laboratory Measurements

Seven washers of each type were conditioned in water

at 95° C for l4 days. Seven other washers were similarly

aged in air. The change in weight and the penetration of

a ball about 0.4 mm in diameter under a load of about 115 g

were measured to determine the effect of these aging

conditions

Two washers of each type were conditioned in water

at 95° C for 6 days. These washers were compressed 20$

and placed in water at 95° C for 72 hours. After recovery

for 50 minutes in water at 25° C, the set was measured.

The results of these laboratory tests are given in

Table 5. The fiber and sandwich washers absorb a large

amount of water within 1 day. Water soluble material is

then leached from these washers. The rubber washers can

be divided into 2 groups with respect to water absorption.

Polychloroprene washers absorb about 50$ of their weight

and the others about 5$. Of the plastic washers. Nylon

washers absorb about 7$ of their weight, Delrin washers

about 1$, and Teflon washers absorb a negligible amount

of water.

The weight loss in air after l4 days at 95° C was

less than 1$ for NBR-1A and the 5 plastic washers. The

polychloroprene washers lost almost 5$ In weight. Except

for F-2A and NBR-2A, the other washers lost from 4 to 10$.

Washer F-2A gained in weight after losing about 4$ the

first day. Presumably the increase resulted from oxidation.
8

Conditioning the washers in air at 95° C for l4 days

caused an increase in stiffness (decreased penetration of

ball) of all washers except F-2A and the 5 plastic washers.

These results should be indicative of the stiffening that

occurs during shelf-aging of washers.

Conditioning the washers in water at 95° C for l4 days

caused a decrease in stiffness (increased penetration of

ball) of all washers except NBR-5A, Delrin, and Teflon

washers. NBR-5B, R-1A, R-1B, and Nylon washers softened

only slightly.

The compression set of washers NBR-1A and NBR-2A

did not exceed 1 5$; whereas , that of the other washers

was high ranging from 28 to jQfo.

Discussion

A comparison of the laboratory results in Table 5

and the simulated service results in Tables 2, 3, and 4

show very little correlation between them. Even if the

comparison is restricted to the rubber washers, the

laboratory and service results are not correlated in any

simple manner.

It was originally planned to conduct service tests

on some of the washers conditioned l4 days at 95° C in

air and in water. Lack of time and funds prevented

making these tests before the project was terminated on

June 30, 1961. Such tests might have indicated some

degree of correlation. In any case, further work would

be necessary to determine the characteristics of washers

responsible for their performance in service. With our

present knowledge., a service test would be the only

satisfactory means for evaluating faucet washers

procured by the Government.

A change of 180 degrees in the angular position of

the stem in the service test described in this report

corresponds to a linear motion of 0.125 inch. Therefore,

the angular degrees in Tables 2, 3<> and 4 can be converted

to changes in thickness of the washer. On this basis, the

following procedure and requirement are suggested for

specification purposes

The washer shall not decrease in thickness by more than

0.050 inch where it contacts the faucet seat when tested

in the following manner:
9

Each of four washers selected at random from the lot shall

be subjected to 15.? 000 closures in a simulated service test

using standard faucets having smooth replaceable seats.

The closures shall be made at a rate of 45±5 per minute.

The temperature of the water flowing through the faucet

at each opening shall be 85±2° c. The pressure of the water

shall be at least 8 psi when the faucet is open and at

least 25 psi when the faucet is closed. The closing torque

on the faucet stem shall be between 20 and 21 pound-inches.

The decrease in thickness of the washer in contact with

the seat shall be determined from the angular position of

the faucet stem at the start and end of the test and the

lead of the screw on the stem] the full closing torque

shall be applied to the stem during all measurements.

The average of the values obtained for the four washers

shall be used for determining compliance with the requirement . The excellent performance of the Nylon washer

justifies field trials of this washer. It is important

to note that this washer is harder than the fiber washers.

It is expected that a tight closure with this washer can

be obtained only with seats in good condition. The

psychological factor may also be important in using this

washer. For these reasons s it is recommended that an

experimental field trial precede .any extensive use of

this washer.

Rubber washers can be obtained that, perform, as

satisfactorily in hot water as fiber washers. Since

washers in actual use are subjected to milder conditions

than in the simulated service test* the performance of

rubber washers may be expected to be relatively better.

ThuSj, there appears to be no need of using different

washers for hot and cold water faucets.

Conclusion

1. Further work is needed to determine the characteristics

of washers that govern their performance in service.

2. A simulated service test is required to evaluate

faucet washers in the light of our present knowledge.

5. The excellent performance of Nylon washers in a

simulated service test warrants an experimental

field trial of these washers.

4. Rubber washers satisfactory for hot and cold water

service are available, eliminating the need for

stocking two types of washers

USCOMM-NBS-D C

Table 1

Composition and Hardness of Washers

Code* Composition Hardness- IRHD

Min. Max. Ave.

F-1A Fiber 99.0 99.8 99.5

F-2A ii 99.6 99-9+ 99.9

F-3A ii 99.0 99.7 99.5

S-1A Sandwich 99.4 99.9+ 99.7+

S-2A it 99.2 99.9 99.7

S-3A tt 98.7 99.8 99.5

NBR-1A Nitrile Rubber 93.5 94.8 94.5

NBR- 2A ti 88.2 91.6 89.9

NBR-3A n 94.1 97.3 95.8

NBR-3B it 96.6 98.5 97.6

CR-1A Polychloroprene 96.3 98.5 97.5

CR-1B rt 97.0 98.2 97.6

CR-2A ii 94.1 97.3 96.1

CR-2C ji 94.4 96 .

95.7

CR-3A n 95.2 98.2 97.4

CR-3B tl 94.1 98.0 96.9

CR-4A II 89.9 93.3 91.4

cr-4b II 93.7 98.2 96.0

cr-4d It 93.7 98.0 96.4

CR-5A II 91.6 95.2 93.4

CR-5B II 91.2 94.8 93.4

CR-6A II 94.4 98.0 96.9

CR-6B II 96.3 98.2 97.4

R-1A Blend NR and SBR 95.2 97.6 97.0

R-1B it 94.8 97.3 96.0

D-1A Delrin 99.9 99.9+ 99.9+

N-1A Nylon 99.8 99.9+ 99 . 9+

T-1A Teflon 99. *4 99.8 99.6

* Suffix letters signify the following:

A- flat washer

B- beveled washer

C- concave bevel

D- special flat washer in brass holder designed to

permit closure without rotation
Table 2

Performance of Commercial Washers at 85° C

Washer Test Change in Angular Degrees of Stem After

1000 closures 5000 closures 15000 closures

F-1A 2 13 34 42

F-2A 2 22 27 36

F-2A 3 12 30 42

F-3A 3 17 28 38

S-1A 2 16 29 52

S-2A 2 19 32 45

S-3A 3 27 44 52

NBR-1A 2 14 31 59

NBR-2A 2 18 43 87

NBR-3A 2 54 99 136

NBR-3B 3 45 96 139

CR-1A 2 28 4l 64

CR-1B 3 20 29 45

CR-2C 2 18 56 88

CR-3A 2 36 66 86

CR-3B 3 20 53 65

CR-4A 3 56 87 134

cr-4b 3 19 38 59

CR-4N 3 34 62-149* 72-160*

CR-5A 2 83 131 _ ** CR-5B 3 37 69 82

CR-6B 3 23 46 60

R-1A 2 28 74 116

R-1B 3 43 124 158

Coefficient of Variation, %

23 20 15

* Each value is the average for two washers

All

other values are averages for four washers • ** Three of the four washers wore through before

15*000 closures were made.
Table 5

Effect of Cold and Hot Water on Washer Performance

Washer Change in Angular Degrees of Stem after

1 , 000 - at 5°C

15 * 000 - at 5°C

1^000-

at 85°C

15*000

at 85°

- closures

C Total

F-1A 8 24 6 8 52

F-2A 10 28 5 15 45

F-3A 18 54 5 18 52

S-1A 12 24 10 19 45

S-2A 15 58 9 15 55

S-5A 21 58 7 21 59

NBR-1A 2 9 5 20 29

NBR-2A 2 15 11 48 65

CR-1A 4 9 12 45 52

CR-1B 6 19 15 51 50

CR-4B 5 15 8 42 55

cr-6b 5 17 10 27 44
Table 4

Performance of Plastic and Rubber Washers

Washer Change in Angular Degrees of Stem After

1,000-

at 10°C

15 . 000 - at 10 °C

”i,OO0-

at 85°C

15.000- closures

at 85°C Total

NBR-1A 3 11 8 27 38

NBR-2A 5 14 15 54 68

CR-1A 4 10 9 37 47

D-1A 1 8 6 15 23

N-1A 2 8 3 8 16

T-1A 3 9 7 20 29
Table 5

Results of Laboratory Tests

Washer

Wt . Gain

in WaterJv

Wt. Loss,

in Airl/ Penetration of' Ball Comp.

1

day

14

days

1

day

14

days orig. air£/ water^/ Set2/

~W~ IT % -M M 1° F-1A 46 4i 4.2 5.2 54 22 159 55

F-2A 6 l 57 4.0 2.2 17 17 156 55

F-5A 29 21 5.5 9.7 50 20 155 28

S-1A 57 45 5.6 4.1 27 20 156 58

S-2A 42 50 4.4 5.6 51 24 147 42

S-3A 45 51 4.5 5.5 52 21 145 57

NBR-1A 5 5 0.6 0.9 116 97 145 15

NBR-2A 5 4 0.6 1.5 182 151 226 11

NBR-5A 2 5 1.9 5.7 90 56 89 78

NBR-5B 5 4 2.2 6.2 80 54 95 54

CR-1A 8 55 1.1 2.4 77 54 224 55

CR-1B 8 28 1.2 2.6 76 54 242 59

CR-2A 7 28 1.2 2.7 106 62 259 52

CR-2C 7 29 1.0 2.8 116 69 286 47

Cr-5A 9 58 1.1 2.8 86 57 527 60

CR-5B 7 51 1.0 2.7 94 60 288 47

CR-4A 8 28 1.2 5.0 158 105 345 44

CR-4B 8 25 1.1 2.7 99 65 260 49

cr-4d 4 19 1.0 2.6 92 68 228

CR-5A 8 52 1.0 2.5 156 99 404 49

CR-5B 8 52 1.0 2.6 115 67 552 59

CR- 6A 8 29 1.0 2.6 88 60 262 57

gr- 6b 7 28 0.9 2.7 72 48 257 65

R-1A 2 6 2.6 4.0 106 69 124 49

R-1B 2 5 2.6 5.9 108 74 129 60

D- 1 A _ 0<>9 0.5 10 12 12 55

N-1A - 7

- 0.8 9 11 21 56

T-1A - 0.04 - 0.01 59 42 58 72

1/ At 95° C '1d/ Conditioned l4 days at 95° 0

3/ 72 hrs. in water at 95° C
.

.


FIGURE. 2.

II. S. DEPARTMENT OF COMMERCE

Luther H. Hodges, bead Cary NATIONAL BUREAU OF STANDARDS

A. V. Aatin, Director

THE NATIONAL BUREAU OF STANDARDS

The scope of activities of the National Bureau of Standards at its major laboratories in Washington, D.C., and

Boulder, Colorado, is suggested in the following listing of the divisions and sections engaged in technical work.

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its title. A brief description of the activities, and of the resultant publications, appears on the inside of the

front cover. WASHINGTON, DC.

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Metallurgy. Thermal Metallurgy. Chemical Metallurgy. Mechanical Metallurgy. Corrosion. Metal Physics. Electrolysis and Metal Deposition.

Mineral Products. Engineering Ceramics. Class. Refractories. Enameled Metals. Crystal Growth. Physical

Properties. Constitution and Microstructure. Building Research. Structural Engineering. Fire Research. Mechanical Systems. Organic Building Materials. Codes and Safety Standards. Heat Transfer. Inorganic Building Materials. Applied Mathematics. Numerical Analysis. Computation. Statistical Engineering. Mathematical Physics. Operations Research. Data Processing Systems. Components and Techniques. Digital Circuitry. Digital Systems. Analog Systems.

Applications Engineering.

Atomic Physics. Spectroscopy. Infrared Spectroscopy. Solid State Physics. Electron Physics. Atomic Physics.

Instrumentation! Engineering Electronics. Electron Devices. Electronic Instrumentation. Mechanical Instru- ments. Basic Instrumentation. Physical Chemistry. Thermochemistry. Surface Chemistry. Organic Chemistry. Molecular Spectroscopy. Molecular Kinetics. Mass Spectrometry.

Office of Weights and Measures. BOULDER, COLO.

Cryogenic Engineering. Cryogenic Equipment. Cryogenic Processes. Properties of Materials. Cryogenic Technical Services. Ionosphere Research and Propagation. Low Frequency and Very Low Frequency Research. Ionosphere Research.

Prediction Services. Sun-Earth Relationships. Field Engineering. Radio Warning Services.

Radio Propagation Engineering. Data Reduction Instrumentation. Radio Noise. Tropospheric Measurements.

Tropospheric Analysis. Propagation-Terrain Effects. Radio-Meteorology. Lower Atmosphere Physics.

Radio Standards. High Frequency Electrical Standards. Radio Broadcast Service. Radio and Microwave Materials. Atomic Frequency and Time Interval Standards. Electronic Calibration Center. Millimeter-Wave Research.

Microwave Circuit Standards. Radio Systems. High Frequency and Very High Frequency Research. Modulation Research. Antenna Research.

Navigation Systems.

Upper Atmosphere and Space Physics. Upper Atmosphere and Plasma Physics. Ionosphere and Exosphere

Scatter. Airglow and Aurora. Ionospheric Radio Astronomy.
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