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Decoding ASTM A121

ASTM A121 outlines the specifications for metallic-coated carbon steel barbed wire, ensuring it meets specific quality and performance standards for applications.

This specification covers metallic-coated carbon steel barbed wire, consisting of a strand of two wires. The barbed wire is available with aluminum, zinc, and zinc-aluminum-mismatched alloy coatings with a number of coating weights. The barbed wire is classified as coating Type A, Type Z, and Type ZA. The sizes and constructions for barbed wire furnished under this specification shall conform the requirements. Sampling, testing and inspection of the material shall be performed in accordance with this specification.

  • Barbed Wire: A twisted or woven wire strand or strands having projecting barbs.

  • Barb: A short piece of wire with sharpened ends, twisted or wrapped around the strand wire(s) of barbed wire.

  • Strand Wire: The wire or wires that form the main body of the barbed wire, to which the barbs are attached.

  • Metallic Coating: A layer of metal, such as zinc or aluminum, applied to the steel wire to provide corrosion protection.

  • Galvanized: Coated with zinc.

Design  Number—Numbers  describing  standard  sizes and constructions. Strand Wire Diameter (Gauge)-Barb Points Number (4 or 2)-Barb Spacing (in.)-Barb Diameter (in.) Barb Shape (R for Round, F for Flat).

Metallic Coating Type: The metallic coating is a critical aspect of the barbed wire, providing corrosion resistance and extending its service life.

1  Coating Type A—Made from aluminum-coated strand wire. 

2  Coating Type Z—Made from zinc-coated strand wire. 

3  Coating  Type  ZA—Made  from  zinc-5% aluminum-mischmetal alloy (Zn-5AL-MM) coated strand wire. See Table 3.

Metallic Coating Class—The specified amount of coating (coating weight (mass)) on the strand wire, Class 1 or Class 3 in oz/ft² or g/m² .

Grades:

1  Standard Grade—Barbs spaced on 4 or 5 in. (102 or 127 mm) centers.

2 High-Security Grade—Barbs spaced on 3 in. (76 mm) centers with Coating Type A, Z, or ZA only.

  • ASTM designation (A121)

  • Type of coating (e.g., zinc-coated)

  • Coating class (if applicable)

  • Wire gauge

  • Barb spacing

  • Coil length and weight

  • Any special requirements

A90/A90M Test Method for Weight [Mass] of Coating on Iron and Steel Articles with Zinc or Zinc-Alloy Coatings

A428/A428M Test Method for Weight [Mass] of Coating on Aluminum-Coated Iron or Steel Articles

A641/A641M Specification for Zinc–Coated (Galvanized) Carbon Steel Wire

A700 Guide for Packaging, Marking, and Loading Methods for Steel Products for Shipment

A809 Specification for Aluminum-Coated (Aluminized) Carbon Steel Wire

A856/A856M Specification for Zinc-5 % Aluminum-Mischmetal Alloy-Coated Carbon Steel Wire

A902 Terminology Relating to Metallic Coated Steel Products

12 gauge 0.104 in. (2.64 mm)

12 1/2  gauge 0.099 in. (2.51 mm)

13 gauge 0.092 in. (2.34 mm)

13 1/2 gauge 0.086 in. (2.18 mm)

13 3/4  gauge 0.083 in. (2.11 mm)

14 gauge 0.080 in. (2.03 mm)

15 1/2  gauge 0.067 in. (1.70 mm)

16 1⁄2  gauge 0.058 in. (1.47 mm)

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