Electro Hardware MM1309M12-MSC Hex Standoff 4-40 1/4in Steel

Product Description

The ELECTRO HARDWARE MM1309M12-MSC is a male-male hex circuit board standoff designed for use in electronic assemblies and PCB mounting applications. This fastener accepts a 4-40 thread on both ends and features a hexagonal body shape that allows for wrench engagement during installation. The overall length is 0.25 inches with a body length of 0.25 inches and a width across flats of 0.1875 inches. Constructed from Grade 2 steel with a zinc-plated finish per QQ-S-633, this standoff provides corrosion resistance in typical indoor electronics environments. It is sized and threaded to work with standard 4-40 fastener hardware common in PCB and chassis assembly work.

This standoff is used in residential and commercial electronics assemblies where circuit boards require secure, fixed-height separation from a chassis, panel, or secondary board. Typical installation scenarios include control boards, instrumentation enclosures, and electronic subassemblies in HVAC control panels, electrical equipment, and similar trade applications. The compact 0.25-inch OAL makes it suitable for tight-clearance PCB stacking. It ships individually and is available in single-unit quantities.

Key Features

• Male-male hex configuration with 4-40 threading on both ends for secure double-sided fastening
• Hexagonal body shape allows wrench engagement for torque-controlled installation
• Grade 2 steel construction meets QQ-S-633 fastener standard
• Zinc-plated finish provides corrosion resistance for indoor electronics environments
• Compact 0.25-inch overall length suits tight PCB clearance applications
• Length tolerance of -0.005 to 0.005 inches ensures consistent stack height

Compatibility

Designed as a standard 4-40 male-male hex standoff compatible with circuit boards and chassis panels drilled and tapped to 4-40 specifications using the inch measurement system.

Installation Notes

Installation is performed by electronics technicians or electricians working on control panel and PCB assemblies. Always de-energize and discharge the circuit board assembly before installing or removing standoffs. A hex wrench or nut driver sized for 3/16-inch across flats is recommended for proper engagement. Avoid over-tightening, as the 4-40 thread and small body diameter can be susceptible to thread damage if excessive force is applied.