Holo-krome 87078 Flat Socket Cap Screw M5x0.8 40mm

Product Description

The HOLO-KROME 87078 is a metric flat socket cap screw designed for flush or countersunk fastening applications in precision assemblies. It features a 90-degree flat head with a 3.00 mm hex socket drive and is manufactured from grade 12.9 alloy steel, giving it high tensile strength suited to demanding mechanical connections. The black oxide finish provides mild corrosion resistance and a low-reflectance appearance. With an M5x0.8 thread size and an overall length of 40.00 mm, this screw is partially threaded and carries a thread fit class of 4G. Licensed trades and industrial maintenance professionals install this fastener where a low-profile head is required to sit flush with a mating surface.

This flat socket cap screw is used in applications that demand a recessed, flush-mount fastener - common in machine tool assemblies, fixture plates, robotics frames, and mechanical enclosures. The 90-degree countersunk head mates with standard metric countersunk hole profiles. The hex socket drive accepts a 3.00 mm hex key, making it suitable for tight-clearance installations where a wrench cannot be used. Partially threaded shanks provide improved clamping force between joined parts. This screw is sold in packages of one unit with a minimum order quantity of 10 units.

Key Features

• Grade 12.9 alloy steel construction for high tensile and proof load strength
• 90-degree flat head seats flush in standard metric countersunk holes
• 3.00 mm hex socket drive for use with a standard hex key in tight spaces
• Black oxide finish for mild corrosion resistance and low reflectance
• Partially threaded shank for improved clamping between mating components
• Conforms to ANSI B1.13M and ISO 10642 fastener standards

Compatibility

Designed as an OEM-style metric flat socket cap screw conforming to ANSI B1.13M and ISO 10642, suitable for use in any application requiring an M5x0.8 countersunk hex socket fastener with a 40.00 mm overall length.

Installation Notes

Installation is typically performed by machinists, millwrights, or mechanical assemblers. Before installation, ensure the mating countersunk hole is drilled and chamfered to the correct 90-degree angle and diameter for an M5 flat socket screw. Use the correct 3.00 mm hex key to drive the fastener; an undersized or worn key risks rounding the socket. Grade 12.9 fasteners should not be reused in critical load-bearing joints once they have been torqued to specification on a prior installation.