MAR 2 6 1968

NATIONAL BUREAU OF STANDARDS REPORT

9800

EXAMINATION OF

GALVANIZED (ZINC COATED)

STEEL SHEET SAMPLES

To

Department of State

Agency for International Development

<^BS>

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
THE NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards1 provides measurement and technical information services

essential to the efficiency and effectiveness of the work of the Nation’s scientists and engineers. The

Bureau serves also as a focal point in the Federal Government for assuring maximum application of

the physical and engineering sciences to the advancement of technology in industry and commerce. To

accomplish this mission, the Bureau is organized into three institutes covering broad program areas of

research and services:

THE INSTITUTE FOR BASIC STANDARDS . . . provides the central basis within the United

States for a complete and consistent system of physical measurements, coordinates that system with the

measurement systems of other nations, and furnishes essential services leading to accurate and uniform

physical measurements throughout the Nation’s scientific community, industry, and commerce. This

Institute comprises a series of divisions, each serving a classical subject matter area: —Applied Mathematics—Electricity—Metrology—Mechanics—Heat—Atomic Physics—Physical

Chemistry—Radiation Physics—Laboratory Astrophysics2—Radio Standards Laboratory, 2 which

includes Radio Standards Physics and Radio Standards Engineering—Office of Standard Refer- ence Data. THE INSTITUTE FOR MATERIALS RESEARCH . . . conducts materials research and provides

associated materials services including mainly reference materials and data on the properties of materials. Beyond its direct interest to the Nation’s scientists and engineers, this Institute yields services

which are essential to the advancement of technology in industry and commerce. This Institute is or- ganized primarily by technical fields: —Analytical Chemistry—Metallurgy—Reactor Radiations—Polymers—Inorganic Materials—Cryogenics2—Office of Standard Reference Materials.

THE INSTITUTE FOR APPLIED TECHNOLOGY . .

. provides technical services to promote the use of available technology and to facilitate technological innovation in industry and government. The

principal elements of this Institute are: —Building Research—Electronic Instrumentation—Technical Analysis—Center for Computer Sci- ences and Technology—Textile and Apparel Technology Center—Office of Weights and Measures —Office of Engineering Standards Services—Office of Invention and Innovation—Office of Vehicle

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Evaluation Laboratory—NBS/GSA Testing Laboratory.

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2 Located at Boulder, Colorado, 80302.

3 Located at 5285 Port Royal Road, Springfield, Virginia 22151.
NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT MAR 2 6 J968 NBS REPORT

3120625 (G-39190) 9800

EXAMINATION OF

GALVANIZED (ZINC COATED)

STEEL SHEET SAMPLES

By

W. F. Gerhold

Engineering Metallurgy Section

Sponsor

Department of State

Agency for International Development

IMPORTANT NOTICE NATIONAL BUREAU OF S' for use within the Government, and review. For this reason, tl whole or in part, is not authc Bureau of Standards, Washing

the Report has been speciticall;

Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST) on October 9, 2015

3ss accounting documents intended

; subjected to additional evaluation

2 listing of this Report, either in

le Office of the Director, National by the Government agency for which

copies for its own use. <NBS>

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

Examination of

GALVAN I ZED (ZINC COATED)

STEEL SHEET SAMPLES

Submi tted by

Department of State

Agency for International Development

Reference : (a) Department of State, Agency for International

Development letter, dated February 8 , 1968 .

I n t roduct i on : Two galvanized (zinc coated) steel sheet samples were

submitted under Reference (a). It was requested that these samples

be examined to determine if the weight of the zinc coating was in

conformance with that specified in ASTM Specification A446-67' ' for 1.25 commercial coating class. The minimum weight of coating

specified for this coating class in the single spot test is 0.80 oz/ft

Procedure : There were visible indications of corrosion and abrasive

damage on one surface of each of the samples submitted. The other

surface of each sample had been painted but there were indications

of paint failure and subsequent corrosion on these surfaces also. A

specimen of suitable size was obtained from an area on each sample

where corrosion and abrasion were minimal. The paint coatings were

stripped from these specimens and the specimens were then cleaned and

we i ghed

The zinc coating was stripped from the specimens by immersion in

a 1:1 hydrochloric acid solution. The specimens were then rinsed in

water, dried and reweighed.

The weight of coating was then determined by use of the following

formu 1 a

(l) Standard Specification for Zinc Coated (Galvanized) Steel Sheets

of Structural Quality, Coils and Cut Lengths.

2

Wi - WP

C = -L- X G X K

W2

where:

C = wt . of coating (oz/ft 2 of sheet)

W | = original weight of specimen (g)

Wp = weight of stripped specimen (g)

G = thickness of stripped sheet (in)

K = a constant (655)

The weights of coating thus obtained for the specimens were O.87 oz/ft 2

. and 0 . 9^ oz/ft 2

. Both samples had coating weights within the specification

limits for 1 .25 commercial coating class. The original weight of

coating on the samples may have been greater than that determined, as any corrosion during service would have reduced the amount of zinc on the surface.

USCOMM-NBS-DC