ZINC
COATING
The Percent zinc coating on d" diameter wire coated with
coz/ft2zinc is:
(6) 
Example : for 0.090" diameter wire coated 0.3 oz/ft2
:
(6) 
The weight of zinc on d" diameter wire coated with p% zinc is
:
(7) 
Where :
p% = weight percent of zinc(%)
c = zinc coating weight (oz/ft2)
d = wire diameter(inch)
Example: for 0.090" diameter wire, 2.00% zinc coating
weights :
* Refer to Page 301, Volume 1, Steel Wire Handbook
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Reduction in Area:
Step reduction, drawing wire from di-1to di
(8) 
Examples :drawing from step 3 to step 4:
r4[1-(0.090/0.102)2] X 100
drawing 0.102" wire to 090"
r = [1-(0.090/0.102)2 X 100 = 22.15%
Total Reduction, drawing from d0 to di
(9) 
Examples :at step 4: r = [1-(d4/d0)2]
X 100
drawing 7/32" rod to 0.102":
r = [1 - (0.102/0.219)2] X 100 = 78.31%
Overall reduction, drawing from d0 to df
(10) 
Examples :drawing 7/32" to 0.090" :
rf= [1-(0.090/0.219)2] X 100 = 83.11%
NOTES :
1. Reduction in area is not additive, rf is not f1
+ r2 + ... + rn
2. Reduction is always positive.
3. Reduction is never larger than 100%.
4. For ferrous wire, step reduction is usually between 7% and 38%
(limits depend on the product).
5. For overall reduction greater than 85%, the process has to be
carefully designed.
6. Clue : for final diameter of one half the original, reduction is
75%.
To Compute the diameter from reduction :
(11) 
Example:Drawing 7/32" rod 25% reduction:
Given the small diameter, the large diameter is:
(12) 
Where:
r = drawing reduction in area(%)
d = wire diameter(inch)
Example: For an overall reduction of 83.1%, an 0.090"
wire will require a starting diameter of:
do =
The Required Percent Reduction Between the Bottom and Top Block
of a Double-Draw Single-Block Frame:
Total required reduction at the second hole
(13) = 100% - |
