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BULLETIN 1216, U. S. DEPARTMENT OF AGRICULTURE. 
strand and obtain the mean diameter. The area calculated from 
the mean diameter of the wire multiplied by the number of wires 
in each strand and by the number of strands gives the aggregate 
area of the wires in the rope. 
4. The test specimen for the tension test shall be free from 
bends and not less than 4 feet in length. Before cutting the test 
pieces from the coil of rope the ends must be " served " or wound 
about with wire for a length of about 1 inch to prevent the 
strands from unlaying. 
PREPARATION OF SPECIMEN FOR TEST. 
Preparation 5. A socket shall be attached to each end of the rope for the 
of specimens, tension test. In preparing the rope for socketing, the ends 
are first served or wound around with fine soft wire for a 
length of about one-half inch at the ends and also at a distance 
from the ends equal to the lengths of the basket of the socket. 
The ends of the rope are then slipped through the socket and 
the serving wire removed from the end only. Unlay the strands, 
separate the individual wires, and straighten them. Cut out the 
hemp center, if any. Cleanse the wire thoroughly with kerosene 
or gasoline and wipe dry. Tin the wires by dipping first in a 
mild zinc chloride solution and then in molten zinc. When re- 
moved from the latter, they should be knocked with a stick 
or hammer to remove the excess zinc. Repeat the tinning until 
all the wires are thoroughly coated. Pull the frayed ends back 
into the basket of the socket and spread the wires evenly in the 
socket and even with the top of the basket. Put fire clay or 
asbestos fiber around the rope at the bottom of the socket, heat 
the socket for a short time with a blowtorch, and pour in molten 
pure zinc (not babbitt or lead). 
6. Put the sockets through the heads of the testing machine 
and place pins through the eyes of the sockets, using steel blocks 
on each side of the socket, if necessary, to secure a firm bearing 
(pins should be as large as possible). Apply the load slowly 
to give the strands and wires opportunity to properly bed upon 
one another during the application of the load. Continue loading 
until fracture of one or more strands of the rope occurs. 
7. The uniformity of the galvanizing or spelter coating, if any, 
shall be determined in accordance with the method for uniformity 
of spelter coating. 
TEST FOR UNIFORMITY OF GALVANIZING OR SPELTER 
COATING ON WIRE. 
Coating. 1. This method gives in detail the test to be applied to gal- 
vanized wire. 
2. (a) Coating. — The galvanizing shall consist of a continuous 
coating of pure zinc of uniform thickness, and so applied that it 
adheres firmly to the surface of the iron or steel. The finished 
product shall be smooth. 
Cleaning. 3. (&) Cleaning. — The sample shall be cleaned before testing, 
first with Carbona, benzine, or turpentine, and cotton waste (not 
with a brush), and then thoroughly rinsed in clean water and 
wiped dry with clean cotton waste. 
4. The samples shall be clean and dry before each immersion 
in the solution. 
Solution. 5. (c) Solution. — The standard solution of copper sulphate 
shall consist of commercial copper sulphate crystals dissolved in 
cold water, about in the proportion of 86 parts, by weight, of 
crystals in 100 parts, by weight, of water. The solution shall be 
neutralized by the addition of an excess of chemically pure 
cupric oxide (CuO). The presence of an excess of cupric oxide 
will be shown by the sediment of this reagent at the bottom 
of the containing vessel. 
6. The neutralized solution shall be filtered before using by 
passing through filter paper. The filtered solution shall have a 
