What is a threaded insert?

A threaded insert or widget is cylindrical, square or hexagon in shape and can be manufactured in brass, steel, stainless steel, Aluminium or Zinc Alloy. A threaded insert is typically used with plastics, metals, wood and composites. An insert is used to avoid damage to the material it is being inserted into and to allow a metal thread in a different type of material such as plastic or wood.  Most inserts are post moulded, the outer knurl of the insert enable it to lock into a predrilled or moulded hole. The inner part of the insert is usually threaded which allows it to be used with a fastener.
At InsertsDirect we sell a variety of brass threaded inserts which are generally used in thermoplastic injection mouldings. 
The Multifit (Multi-purpose) range enables the user to install the insert by either hot or cold methods. The location spigot and knurl allow the insert to locate squarely in drilled or moulded-in holes.
The Heatfit (Ultrasonic) range are installed using heat staking or ultrasonic equipment. With opposing herringbone knurling on the outside, this type of knurl allows for a greater retention in the plastic. As the insert is double ended the insert can be used during automatic feeding.
The Screwfit (Screw In) range are self-tapping inserts which installed in pre-drilled or moulded holes.  As this insert is double ended, it allows the insert to be installed either way. This type of insert offers very high torque and pull out performance.
The Pressfit (Press In) range are self-broaching and are pressed in cold. These inserts are easily installed and no expensive equipment is required. The Pressfit Expandable (Press in) range are installed using a slow squeezing action and must be allowed to rotate during the installation. This insert is a good alternative as it does not require expensive equipment. This insert has been designed with a diamond knurl and the slot which allows the insert to expand during screw insertion.
The Mouldfit (Mould in) range is designed to be moulded in rather than post mould insertion. This insert is blind ended in design which prevents any plastics entering the internal thread. 
Another type of insert which is commonly used with wood, is our Woodfit (Insert Nut Type A,C,D,E)  range. Manufactured in Zinc Alloy and plated, this type of insert offers a strong permanent thread for soft wood and chipboard. The external thread on this insert ensures strong resistance against pull-out from vibrations. These inserts are easy to install with a hex drive tool.
If a hard wood is being used we do recommend using a Stainless Steel Woodfit Insert Nut). Stainless steel offers greater corrosion resistance and does not stain or rust when exposed to the elements.
Unheaded_Multifit_Insert-SectionHeaded_Screw_In_Woodfit-Inserts_for_WoodHeaded_Stainless_Steel_Woodfit_Insert-Product
 
 
 
 
 
 
 
 
 
 

Galvanic Corrosion

Galvanic corrosion occurs when two metals are placed in electrochemical contact in the presence of an electrolyte.

This then results in corrosion of the less resistant of the metals in question (anodic/anode), while the stronger; more noble cathodic metal will corrode much slower.

Seeing the image listed below, the table provides an insight as to where this can occur:

Galvanic_Corrosion_Chart