Value Collection 39389 Hex Cap Screw 7/16-20 X 3.5 in Grade 8

Product Description

The VALUE COLLECTION 39389 is a partially threaded hex head cap screw designed for high-strength fastening applications in mechanical, structural, and industrial assemblies. Manufactured from Grade 8 steel with a zinc yellow dichromate finish, this fastener delivers superior tensile strength and corrosion resistance compared to lower-grade alternatives. The 7/16-20 UNF thread size and 3.5-inch length under head make it well suited for close-tolerance applications where fine threads are required for precise clamping force. This screw conforms to ASME B18.2.1 and SAE J429 standards, ensuring dimensional accuracy and mechanical performance that trade professionals and maintenance technicians depend on.

This fastener is appropriate for use in automotive, heavy equipment, agricultural machinery, and general industrial applications where Grade 8 strength is specified. The fine UNF thread pattern provides increased resistance to loosening under vibration and allows for finer torque adjustment during installation. Partial threading leaves a smooth shank section beneath the head, which provides a bearing surface in clearance holes and helps resist shear loads. It is commonly used by millwrights, maintenance mechanics, and assembly technicians working in demanding mechanical environments.

Key Features

• Grade 8 steel construction for high tensile and proof load strength
• Zinc yellow dichromate finish provides corrosion resistance and identification as a high-strength fastener
• 7/16-20 UNF fine thread for precise torque control and vibration resistance
• Partially threaded shank supports shear load applications and fits clearance holes
• Meets ASME B18.2.1 and SAE J429 dimensional and mechanical standards
• Sold in packages of 25 with a minimum order quantity of 1

Compatibility

Designed as an OEM-style replacement or service fastener for assemblies specifying a 7/16-20 UNF Grade 8 hex head cap screw with 3.5-inch length under head and partial threading per ASME B18.2.1 and SAE J429.

Installation Notes

Installation should be performed by a qualified mechanic or technician using a calibrated torque wrench set to the torque value specified in the equipment service manual for Grade 8 fasteners of this thread size. Always ensure mating threads are clean and free of debris before installation. Do not mix Grade 8 fasteners with lower-grade nuts or threaded components, as this can compromise joint integrity. Follow applicable industry standards and equipment manufacturer guidelines when replacing structural or safety-critical fasteners.