Kovar Alloy Machining Tips from National Electronic Alloys

Kovar Alloy Machining Tips

Kovar Alloy Machining Tips

Looking for people who have direct experience with machining Kovar? Here, at National Electronic Alloys, we want to provide you with some helpful advice on how to handle this controlled expansion alloy. If you are looking to use this material to make parts, and have had trouble in the past, or have never dealt with it before, National Electronic Alloys is here with years of personal experience to guide you through the process.

Nickel alloys usually harden quite rapidly, and the high pressures that machining creates causes hardening and slows down progress, also causing warping in some of the material. Make sure you have a rigid setup, work at a slow speed, and try using sulfurized mineral oil. When machining Kovar (ASTM F15 alloy) it tends to be quite gummy. Tools have a tendency to plow right through the metal rather than chip away at it.

It is important to keep complete control over your heating when machining Kovar, as too much of a heat buildup will cause the alloy to warp. When tooling the metal you must be sure that feathered or wire edges are taken off the tools. And as you always would, make sure every tool is consistently inspected. Carbide tools will give you the highest cutting rate without chipping and should be used in turning jobs without interrupted cuts. If you have interrupted cuts, use high-speed steel tools.

Your drills should be short, as short as you can get them actually. And when reaming, you should be drilling at half speed only while your feed should be around 3 times your drill speed in order for a safe ream. 

Whether you are machining this controlled expansion alloy from coil or sheet, or creating a glass to metal or ceramic to metal seal, we hope that some of the above Kovar machining tips will be useful for your next application. For additional machining tips please see or Kovar Machinability PDF or contact us for a Material Safety Data Sheet on Kovar or any other expansion alloy.