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D5933-19 – Standard Test Method Technical Guide
ASTM D5933-19 is a standard specification for 2 5/8-inch and 4-inch diameter metal shear plates used in wood construction. It standardizes dimensions and materials to ensure quality and reliability in connections. This specification is referenced in design and purchase documents to assure meeting minimum standards.
📐 Product Classification and Types
The specification covers two diameters commonly used in North American timber construction: 2 5/8 in. (66.7 mm) and 4 in. (102.1 mm). The 2 5/8 in. shear plate is manufactured from stamped steel or malleable cast iron, while the 4 in. size is exclusively malleable cast iron. These shear plates are used in load-transfer connections as per the National Design Specification for Wood Construction.
| 🟦 Diameter | 📏 Material | 📐 Reference Standard |
|---|---|---|
| 2 5/8 in. (66.7 mm) | Stamped steel or Malleable cast iron | A47/A47M, A570/A570M |
| 4 in. (102.1 mm) | Malleable cast iron | A47/A47M |
⚙️ Materials and Manufacturing Standards
Materials must meet ASTM A47/A47M for ferritic malleable iron castings, A153/A153M for hot-dip zinc coating, and A653/A653M for galvanized steel. Manufacturing ensures products are not brittle and can be installed with proper tools. Steel sheets should conform to A924/A924M for general requirements.
| 📏 Material | 📐 ASTM Standard | ⚙️ Requirement |
|---|---|---|
| Malleable iron | A47/A47M | Ferritic malleable iron castings |
| Steel sheet | A653/A653M | Zinc-coated (galvanized) steel |
| Zinc coating | A153/A153M | Hot-dip process for hardware |
🛠️ Ensure that all shear plates are manufactured to these ASTM standards to guarantee reliable connection performance and corrosion resistance.
📊 Key Specifications
As defined in Section 3, a shear plate is a round, cast, or stamped disk-like device with a flat base and perimeter bearing rim projecting in one direction. It has a central hole for a bolt or lag screw, optionally with a bearing hub. This design facilitates shear transfer between wood members or between wood and steel. Values are stated in inch-pound units, with SI conversions in parentheses for information only. The standard was developed following international principles on standardization.
⚠️ Shear plates must not be brittle and should be installable with standard tools. Always follow manufacturing guidelines for optimal performance.
❓ Frequently Asked Questions
🔍 What is a shear plate?
A shear plate is a load-transfer device used in wood connections. It is a round disk with a flat base and bearing rim, installed using a bolt or lag screw to transfer shear forces between members.
💡 What materials are used for shear plates?
Shear plates are made from stamped steel or malleable cast iron, conforming to ASTM standards such as A47/A47M and A570/A570M for material quality.
⚡ What diameters does this specification cover?
The standard covers 2 5/8-inch (66.7 mm) and 4-inch (102.1 mm) diameters, as specified for timber construction applications.
📌 Are there any safety considerations?
No specific hazards are known, but shear plates must not be brittle. Proper tools should be used for installation to ensure safety and performance.