Holo-krome 76542 Hex Socket Cap Screw M20 X 2.50 Alloy Steel

Product Description

The HOLO-KROME 76542 is a metric hex socket cap screw used in mechanical assemblies, structural joints, and equipment maintenance applications requiring a high-strength fastener. It features an M20 x 2.50 thread size with a 180 mm length under the head and is partially threaded, making it well-suited for clamped-joint applications where thread engagement is intentionally limited. The screw is manufactured from alloy steel to a Grade 12.9 material specification and finished with a black oxide coating that provides mild corrosion resistance and a low-reflectance surface. Licensed HVAC, plumbing, electrical, and mechanical technicians regularly use this fastener when servicing or assembling industrial equipment frames, equipment mounts, and enclosures.

This fastener is designed for use in metric-dimensioned equipment and machinery. The M20 thread size and 180 mm body length suit it to medium-to-heavy structural connections found in commercial HVAC unit frames, pump housings, electrical enclosure mounting, and general industrial assembly. A hex socket drive requires a standard hex key or Allen-style driver, allowing installation in confined clearances where a wrench cannot be used. The partial threading is particularly useful in applications requiring a shoulder or grip-length fit between mating components.

Key Features

• M20 x 2.50 metric thread with 180 mm length under head
• Grade 12.9 alloy steel construction for high tensile and proof load strength
• Black oxide finish for mild corrosion resistance and reduced surface reflectance
• Partially threaded body suited to clamped-joint and grip-length applications
• Hex socket drive allows installation in restricted-access locations
• Meets ANSI B1.13M, DIN 912, ISO 4762, and ISO 898-1 fastener standards

Compatibility

Designed as an OEM-style and general-service replacement hex socket cap screw for metric-threaded applications requiring an M20 x 2.50 Grade 12.9 fastener conforming to DIN 912 or ISO 4762 dimensional standards.

Installation Notes

Installation should be performed by a qualified mechanic or tradesperson familiar with metric fastener torque requirements for Grade 12.9 alloy steel hardware. Always verify thread engagement depth and confirm mating threads are clean and free of debris before driving the screw. Use a properly sized hex key or socket driver rated for the drive size to avoid rounding the socket recess. Follow applicable equipment manufacturer specifications and relevant codes for fastener torque and joint preload.