Specialinsert Mubux 851 M5 Brass Threaded Insert

Description

The Mubux 851 M5 insert is an extra-short brass threaded bushing for adding a reusable metric thread to rigid thermoplastic parts. Its compact 5 mm length suits molded components with limited wall depth, while angled exterior ribs engage the prepared hole around the insert. The M5 internal thread accepts matching machine screws for assemblies that may need service or repeated removal.

Designed for Rigid Thermoplastics

Series 851 inserts are intended for rigid, preferably molded thermoplastic materials. The short brass body can be installed with pressure, heat, or ultrasonic equipment when the process and material support that method. During insertion, the outside profile displaces and grips the surrounding plastic. The part geometry is designed to reduce radial stress compared with a large expanding fastener, which can help on compact bosses and thinner surrounding walls.

Material behavior varies between resins, filled compounds, molding conditions, and boss designs. Run preliminary assembly tests before production to establish the correct hole size and insertion settings. A controlled trial should confirm boss integrity, thread alignment, pull-out performance, torque resistance, and the appearance of the finished part. Avoid treating a nominal drill size as a complete process specification.

Installation Planning

Prepare a straight hole with enough depth for the 5 mm insert and keep the installation tool aligned with the hole axis. For pressure insertion, support the molded component so the boss is not bent during the stroke. Heat and ultrasonic methods require equipment settings appropriate to the thermoplastic. Seat the insert at the intended surface height without driving it beyond the available wall section.

After installation, allow the assembly to stabilize before checking the M5 thread. Use a compatible screw and control tightening torque for the plastic boss and application. The insert creates the metal thread, but the surrounding thermoplastic and boss geometry still determine the strength of the joint. Confirm performance in the actual part rather than relying only on the insert dimensions.

M5 Insert Specifications

• Manufacturer: Specialinsert
• Product family: Mubux 851 extra-short bushing
• Internal thread: M5
• External diameter: 7.1 mm
• Total length: 5.0 mm
• Recommended reference hole diameter: 6.4 mm
• Minimum reference wall thickness: 2.7 mm
• Material: natural-finish brass
• Thread tolerance: ISO 6H
• Receiving material: rigid thermoplastic

Browse more industrial threaded inserts and fastening hardware when comparing thread sizes and installation styles. Technical sheets and product-family details are available from Specialinsert fastening systems.

Need Help?

Need help comparing insert size, boss dimensions, or installation methods for a thermoplastic part? Call (800) 220-1966 or email [email protected].