Stainless steel fasteners are used in many applications where zero Foreign Object Debris (FOD) is essential – such as in the food industry, clean rooms, electronics, aerospace, satellites, safety critical applications, space and other vacuum environments. The Tangless Kato CoilThread inserts from Advanex, however, have all the characteristics of Tanged threaded inserts, but have eliminated the need for tang break-off and retrieval.
The range can also be easily adjusted or removed after installation. Not only does these offer time savings in applications that usually require counting of each removed tang, but additional savings are made because of the bidirectional design of the Tangless threaded inserts which eliminates the need to orientate each part. Specially designed tools make for fast installation of the insert into the hole.
Tangless Kato CoilThread Inserts are available in a variety of materials, but the standard insert range – made from 304 stainless steel – will meet most application requirements. However, a problem with stainless steel inserts is that when they are used with mating stainless steel fasteners, they can be susceptible to galling – a cold welding process which can occur when pressure builds between the contacting thread surfaces of male and female fasteners during assembly. This may cause some damage to thread forms or, in severe cases, prevent disassembly of the threaded joint.
For applications where galling or magnetic permeability is an issue, Tangless inserts made from an anti-galling wear resistant austenitic stainless steel, comparable with materials like Nitronic 60 are available. This material has strength properties similar to the standard stainless steel material, providing galling prevention without the need for lubrication or plating. This material is also non-magnetic and can be used in manufacturing facilities that have a vacuum process environment or equipment.
For high temperature (550°C) applications, Tangless Inconel X750 inserts are also available. Inconel X750 is a non-magnetic, high corrosion resistance nickel based superalloy with excellent heat resistance and strength characteristics making it ideal for use in demanding applications like gas turbines engines, nuclear applications, well drilling, turbochargers, aeroplane engines and thermal power plants.
For salt water and electrical applications, Tangless Phosphor Bronze inserts are also available. Phosphor Bronze is not quite as strong as Stainless Steel or Inconel X750, but it does possess superior salt water corrosion protection so can be used in a marine environment, states the company. Electrical conductivity allows for use in electrical bonding joints and related operations, while the low magnetic permeability of this material means there is no outside interference to signals. Typical applications include circuit boards, telecommunications control boxes, and medical instrumentation and equipment.
The products are available from ASM Fasteners.