Grade C Nylon Insert Locknut Plain Finish

The Grade C nylon insert locknut with a plain finish is built for demanding fastening applications where strength, security, and vibration resistance are non-negotiable. Designed for inch-sized threads, this locknut is made from hardened carbon or alloy steel—giving it the strength needed for heavy-duty applications in construction, transportation, agriculture, and industrial equipment.

The standout feature of this locknut is the integrated nylon insert, which provides prevailing torque by gripping the bolt threads and preventing loosening due to vibration or dynamic loading. Unlike metal-only locknuts, nylon insert styles allow for softer, controlled engagement and can often be reused a few times without losing their locking integrity (depending on application stress).

The Grade C designation indicates a high-strength steel composition, ideal for applications where load-bearing capacity and durability are critical. Its plain finish (unplated) is ideal for indoor or controlled environments where corrosion is not a concern—or where custom coatings or post-processing will be applied later.

Specifications & Features:

• Type: Nylon insert hex locknut (prevailing torque)

• Grade: C (hardened steel for high-strength applications)

• Finish: Plain (no plating)

• Thread Types: Inch – UNC and UNF available

• Sizes: Typically from 1/4"-20 up to 1"-8 and larger

• Locking Mechanism: Nylon collar insert

• Standards: ASME B18.16.6, SAE J995 (Grade C classification)

Whether you're bolting together structural components or assembling high-torque machinery, the Grade C nylon insert locknut with plain finish provides rugged strength and dependable locking performance without the need for external locking devices.

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