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HDG
Coating Specifications
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At CEMESA
we work and control the quality of the coating taking into account the International Standards
ASTM
A123
(for medium and large size structural elements) and ASTM
A153
(for small elements). In the following image you can see the diagram of both galvanizing processes.
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The following table shows the minimum thicknesses required for the coating, depending on the thickness of the piece to be galvanized:
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Medium-Large Structures
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Material
Category
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Steel
thickness range
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<
1/16" (1.6mm)
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1/16"
to 1/8"
(1.6
to 3.2mm)
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1/8"
ato3/16"
(3.2
to 4.8mm)
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3/16"
to 1/4"
(4.8
to 6.4mm)
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>
1/4" (6.4mm)
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Plates,
Beams, Angular
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45
µm
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65
µm
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75
µm
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85
µm
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100
µm
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Bars,
Rods
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45
µm
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65
µm
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75
µm
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85
µm
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100
µm
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Pipes
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45
µm
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45
µm
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75
µm
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75
µm
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75
µm
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According
to Table 1, ASTM A123/A 123M-09
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The coating thicknesses required for small parts such as nails, screws, nuts, bolts, etc., which undergo centrifugation treatment after removal of the zinc bath are smaller, and are indicated in the following table:
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Small centrifuged parts
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Class of Material
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Averange of specimens
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Individual
specimen
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µm
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g/m2
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µm
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g/m2
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Class A-
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Casting steel
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86
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610
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79
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550
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Class B1-
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Articles with 3/16"
(4.76mm) and over, and over 15” (381mm) in length
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86
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610
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79
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550
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Class B2-
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Articles under 3/16"
(4.76mm) and over 15” (381mm) in length
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66
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458
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53
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381
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Class B3-
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Any
thickness and 15” (381mm) and under in
length
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56
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397
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48
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336
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Fasteners:
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Class C-
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Over Ř 3/8” (9.52mm), washers
3/16” and 1/4” thickness (4.76mm and 6.35mm)
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53
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381
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43
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305
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Class D-
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Under Ř 3/8” (9.52mm),
washers
under 3/16” thickness (4.76mm)
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43
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305
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36
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259
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According to Table 1,
ASTM A153/A 153M-03
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