3/8 Inch External Tooth Lock Washer Hillman Alloy Steel Zinc 100-Pack

Description

Product Overview

The Hillman Group 310086 external tooth lock washer is engineered for precision fastening in demanding industrial and scientific environments. Constructed from high‑grade alloy steel, each washer offers exceptional tensile strength while the zinc plating adds a layer of moderate corrosion resistance, extending service life even in humid or mildly corrosive settings. With an outside diameter of 2.68 inches and a thickness of 0.35 inches, the washer provides a substantial bearing surface that distributes load evenly across the joint, reducing the risk of material deformation.

Designed specifically for 3/8‑inch fasteners, the external tooth profile engages the underside of the bolt head or nut, creating a locking action that resists loosening caused by vibration, thermal expansion, or dynamic loads. The teeth are positioned on the outer edge, keeping the visible surface smooth and aesthetically pleasing—an important factor when the finished appearance of an assembly matters. The glossy silver finish not only enhances visual appeal but also aids in quick visual inspection during assembly and maintenance.

Usage

These washers excel in applications where reliable torque retention is critical. Typical use cases include machinery mounting, equipment enclosures, automotive brackets, and electrical conduit assemblies. The external tooth design is especially advantageous in situations where the fastener head is concealed or where a clean, uninterrupted surface is required for safety or regulatory compliance.

Installation is straightforward: place the washer beneath the bolt head or nut, align the external teeth with the fastener, and tighten to the recommended torque. The hidden‑tooth configuration ensures that the teeth do not protrude, preventing snagging on adjacent components or wiring. Because the washer is zinc‑plated, it can be used in outdoor installations, agricultural equipment, and light‑exposure marine environments without significant degradation.

The 100‑piece pack provides ample inventory for large‑scale projects, routine maintenance, or bulk purchasing programs. Each washer is lightweight (approximately 0.11 kg) yet robust, making it easy to handle in both manual and automated assembly lines.

Why Choose Us

Hillman is a trusted name in fastener technology, delivering products that meet stringent industry standards. Our external tooth lock washers undergo rigorous quality control testing, including tensile strength verification, dimensional accuracy checks, and corrosion resistance assessments. This commitment to quality ensures that every washer performs consistently, reducing the likelihood of premature failure and costly downtime.

We source alloy steel from reputable suppliers and apply a uniform zinc coating using a controlled electro‑plating process. This results in a durable finish that resists flaking and maintains its protective properties over time. Additionally, our packaging is designed for easy inventory management—each box contains a single 100‑piece quantity, clearly labeled with part number 310086 for quick identification.

Customer support is a cornerstone of our service model. Our technical team is available to answer installation questions, provide torque specifications, and assist with any warranty concerns. When you purchase Hillman washers, you receive not only a high‑performance component but also a partnership built on reliability and responsiveness.

Key Features

• Robust alloy steel construction delivers high tensile strength for demanding loads.
• Zinc plating offers moderate corrosion resistance, extending service life in humid environments.
• External tooth design provides secure locking while keeping the visible surface smooth.
• Precise 2.68‑inch diameter and 0.35‑inch thickness ensure optimal load distribution.
• Dedicated customer support and warranty assistance for peace of mind.

FAQ

What size fasteners are compatible with this washer?

The washer is sized for 3/8‑inch diameter fasteners, making it ideal for standard bolts and nuts in that range.

Can the washer be used in outdoor or marine applications?

Yes. The zinc plating provides moderate corrosion resistance suitable for outdoor, agricultural, and light‑exposure marine settings.

How does the external tooth design differ from a standard lock washer?

External teeth engage the underside of the fastener head, delivering a locking action without exposing the teeth on the visible surface, which preserves a clean appearance.

Is the washer reusable after removal?

While the washer can be reused if it remains undamaged, repeated deformation of the teeth may reduce its locking effectiveness. For critical applications, it is recommended to replace the washer after removal.

What is the recommended torque for installation?

Refer to the fastener manufacturer’s torque chart for 3/8‑inch bolts. Generally, a torque range of 8‑12 Nm (70‑110 in‑lb) is appropriate, but always verify against specific equipment requirements.