CarTech KnightCote wire coating is a relatively thin, uniformly applied coating that can be applied to heading-grade wire. CarTech KnightCote coating prevents metal-to-metal contact, provides protection against die wear, and prevents seizure, scoring, galling and welding of parts. It is applied by a proprietary process that results in minimal variation of thickness within or between coils.

This coating can withstand high-impact forces, severe upsetting and extrusion and warm heading. It can be applied to all heading alloys and on either bare or copper-coated wire. It can be used in higher temperature applications than typical molybdenum disulfide-type coatings. It is a solid film that does not deteriorate, is not hygroscopic, exhibits long shelf life and is thermally stable.

Carpenter undertook the development of CarTech KnightCote coating in response to several needs in the heading industry. The most important of these was the ecological problem associated with the removal of copper coatings and the disposal of the resultant spent acid. It was apparent that a coating was needed that would replace copper, while offering similar or superior lubricating properties.

The six criteria established by Carpenter for a suitable heading lubricant were:
1. Easy to apply and control.
2. Exhibits excellent extrudability and cold headability.
3. Relatively easy to remove following fabrication.
4. Stable and exhibits good shelf life.
5. Components are nonpolluting and nontoxic.
6. Thermally stable and suitable for warm/hot heading.

Removal:
CarTech KnightCote coating can be removed by placing the fabricated parts into dilute hot alkaline cleaning solutions (0.2 lb./gal.) at temperatures from 160 to 190°F. Immersion times of four to eight minutes without agitation are sufficient to loosen the coating from the metal surface. Only a portion of the coating is actually removed by stationary treatments, but the balance of the coating can be readily removed by rinsing the parts with water. There are advantages in time savings and removal efficiency if some form of motion during the cleaning operation is employed, such as agitators, vibratory baskets, tumblers, and ultrasonic or circulating solutions.

For certain applications, some customers prefer to have the dual coatings of copper and CarTech KnightCote as an overcoat on their raw materials. The practice used in removing the copper remnants from fabricated parts (dilute nitric acid digestion) should be effective in simultaneously removing copper and CarTech KnightCote coating. The coatings could also be separately removed by initially immersing the parts into an alkaline cleaning solution followed by exposure to nitric acid.

Toxicology & Disposal:
The ingredients of CarTech KnightCote coating are nontoxic and nonpolluting, and there are no known regulations governing the disposal of the components. The limiting disposal factor may be the cleaning solutions containing the components.

Availability:
From the mill, the heading wire can be supplied as CarTech KnightCote coated and cold drawn to finish size in either soaps or oils or dry. Coils can also be supplied as KnightCote coated without final cold drawing.

Applications:
CarTech KnightCote coating has been used to produce a variety of fasteners requiring different degrees of upsetting and extrusion. It has been successfully used on numerous stainless grades and high temperature alloys.

Most heading shops use lubrication on the wire entering the heading machine as well as lubrication within the machine. KightCote coated wire has been found to be compatible with soaps and oils used in these operations. Highly alkaline conditions in this respect should be avoided since they may adversely affect total lubricity.