Simple and Regular Maintenance Lengthens Chuck Life

To help your machine tool's chuck work as effectively as possible, here are some answers to common questions from Spencer Hastert, vice president of the Kitagawa Division-Sumikin Bussan in Illinois. How often should I grease my chuck?

"Regular greasing of the power chuck is too general a concept. In all cases, a power chuck needs to be greased at least once every eight hours of operation. Should you have short cycle times, high rpm requirements or use an aggressive coolant, you may need to grease your chuck even more after-perhaps every four hours.

The timing judgment requires some common sense and observation on your part. Should the chuck show signs of efficiency loss between lubrication cycles, try shortening the time between greasings until the chuck maintains its proper functionality. In any case, adhere to the minimum lubrication schedule. What type of lubrication is required?

All metal surfaces, regardless of how smooth they appear, are not truly smooth. There are microscopic peaks and valleys that can protrude through a lubricating film and create metal-on-metal contact.

Wedge-style chucks can have as much as eight tons of potential friction being applied to the wedge, master jaws and body. Kitagawa recommends a molybdenum-disulfide-based (moly) lubricant with 20% to 25% moly.

This type of lubrication is vastly superior to the lithium-and mineral-based greases on the market today. Moly is essential to providing the required barrier between the metal guide surfaces, especially under heavy loads. Don't allow anyone to tell you that "any grease will do". Insist on the lubrication recommended by the chuck manufacturer.

Is there more to do?

In addition to applying the recommended moly-based grease at intervals that fit your application, other maintenance must be performed.

The chuck should be disassembled, inspected and cleaned every six months. (Refer to the chuck's manual for disassembly procedures.) This will allow the guideways to be cleaned of contamination, chips and coolant. It will also give you a chance to look for burnishing or galling.

By following these simple and regular maintenance steps, it will ensure that your chucks will safely perform to specifications for many years.

The Kitagawa factory recommends Slipkote Chuck-eez grease.

      For more information contact:
      Suzanne Introligator
      Mike Roberts
      Itex Tool & Supply, Inc.
      16745-F North Freeway
      Houston, TX 77090
      800-248-2571
      Fax 281-895-8454
      e mail: itexwkg@ix.netcom.com