F436 Washer: High-Strength Hardened Washers for Demanding Applications
When structural integrity is non-negotiable, every component must perform under pressure. The F436 washer is a critical fastener component engineered specifically for high-strength bolting assemblies. This article provides a detailed overview of the F436 washer, its specifications, compatible standards, and why it’s the preferred choice for engineers and contractors.
What is an F436 Washer?
An F436 washer is a type of hardened round washer designed to be used under the head of a bolt or nut in structural connections. Its primary purpose is to distribute the load of the fastener, prevent embedding into the connected material, and ensure that the clamp load is maintained over time. The “F436” designation comes from the ASTM F436 standard, which governs its mechanical properties and dimensional requirements.
These washers are through-hardened to achieve a specific hardness range, making them significantly stronger than standard, non-hardened (low-carbon steel) washers.
Key Specifications & Features of ASTM F436 Washers
- Standard: Complies with ASTM F436, “Standard Specification for Hardened Steel Washers.”
- Material: Typically made from carbon steel or alloy steel.
- Hardness: Through-hardened to a hardness of HRC 35-45 (Rockwell C scale), providing excellent strength and durability.
- Finish: Commonly available in plain (unfinished), hot-dip galvanized, or mechanical galvanized to match the corrosion protection of the accompanying bolt.
- Function: Prevents the nut or bolt head from digging into the connected material, ensuring proper tension is maintained in the joint.
F436 Washer Dimensions
F436 washers are dimensionally standardized to match the size of the bolt they are used with. The key dimensions are the Inside Diameter (ID), Outside Diameter (OD), and Thickness.
The following table outlines the standard dimensions for some common F436 washer sizes:
| Nominal Washer Size | Inside Diameter (ID) | Outside Diameter (OD) | Thickness |
|---|---|---|---|
| 1/2″ | 0.562″ | 1.250″ | 0.134″ |
| 5/8″ | 0.688″ | 1.500″ | 0.134″ |
| 3/4″ | 0.812″ | 1.750″ | 0.134″ |
| 7/8″ | 1.000″ | 2.000″ | 0.134″ |
| 1″ | 1.125″ | 2.250″ | 0.134″ |
| 1-1/8″ | 1.266″ | 2.500″ | 0.134″ |
Note: Dimensions are per ASTM F436. Thickness may vary slightly for galvanized washers.
Common Applications of F436 Washers
F436 hardened washers are essential in applications where joint integrity is critical. They are commonly specified for:
- Structural Steel Construction: Buildings, bridges, and industrial facilities.
- Heavy Machinery and Equipment.
- Wind Tower and Power Generation Infrastructure.
- Any assembly using ASTM A325 or A490 structural bolts.
F436 vs. A325 Washers: Are They the Same?
This is a common point of confusion. ASTM A325 is a specification for high-strength structural bolts. The specification requires that when a washer is necessary (e.g., for galvanized bolts or when used on slotted or oversized holes), it must be a hardened washer that conforms to ASTM F436.
Therefore, an A325 Washer is, by definition, an F436 Washer. They are the same product, with the name changing based on the bolt assembly it is paired with.
Sourcing F436 Hardened Washers
[Your Company Name] is a leading supplier of high-quality ASTM F436 hardened washers. We offer:
- Full Size Range: Available from stock in all standard sizes.
- Multiple Finishes: Plain, Hot-Dip Galvanized, and Mechanical Galvanized.
- Competitive Pricing & Fast Delivery: We understand the importance of project timelines.
Looking for a reliable source for F436 washers? Contact us today for a competitive quote or to speak with our technical experts about your specific project requirements. Ensure the strength and reliability of your connections with washers that meet the highest industry standards.