All customers want a “quality” product. Having served the metalworking industry in India for 60 years, GMT prides itself on the quality of its chucks and workholding solutions and strives to deliver a product of the best quality to each of its customers. However any machine, or machine part can maintain it’s quality service depending upon how it is used. In other words, it is the careful maintenance of the product at the customer’s end which retains the quality of the product delivered, and therefore the customer plays a very important role in maintaining the quality of a chuck once it becomes his/hers. The careful customer reaps rich rewards.

GMT has specific recommendations for lubricating its chucks. You can download the maintenance manual here.

The Effect of Improper or No Lubrication

If a chuck is not lubricated regularly, the chuck body, wedge and the sliding parts will get corroded, resulting in high friction and loss of clamping force. Here is how the chuck looks after several thousand cycles of use without lubrication:

Here is a close-up of the ground surfaces, after and before damage.

Can you imagine producing a quality component with a chuck like this? The slideway surfaces will also be like this. Not only will there be loss of clamping force, it is also unpredictable. In addition, an improperly lubricated lathe chuck will result in play in the jaws and therefore lead to workpiece chatter.

This results in unsafe clamping of the work piece and the chances of the component falling out during machining are high. In order to avoid this, customers should follow the lubrication and maintenance instructions provided in the chuck instruction manual, with great care.

By contrast, take a look at a newly ground jaw slide. Sliding will be uniform, ie, there will be no stick-slip, and more importantly, the contact area between sliding surfaces will be maximal. So it stands to reason that the clamping force will be maximum.

LUBRICATION

For lubricating the lathe chucks, GMT recommends one of the following grease:

• OKS
• ALTEMP
• MOLYKOTE

Details of suppliers is given in the maintenance manual.

GMT chucks are equipped with several lubrication nipples for even application of grease. To ensure even distribution of the grease inside the chuck, slide the master jaw through full stroke (clamping and de- clamping), at the beginning of every shift.

There are two parts to the lubrication process. The first is on a daily basis:

1: GMT recommends that you slide the master jaw through full stroke (clamping and de-clamping) to ensure uniform distribution of grease on sliding surfaces several times after 500 jaw cycles of the clamping piston. This helps to ensure that the sliding faces remain lubricated, thus maintaining the clamping force.

2: Dismantle and Lubricate the GMT Chuck after a specified number of cycles of use. (We cannot recommend the number of cycles, as it depends on the type of material machined and the machining environment) The maintenance of the chuck should be a part of standard operating procedures for maintenance.

Remember, in extremely contaminated environments such as machining C.I work pieces, dust accumulates between its sliding surfaces very quickly. In such cases, the complete chuck has to be disassembled, cleaned and lubricated much more often. Detailed information is given in the Instruction manual.

Please watch our video on lubrication

Write to us at esales@gmt.co.in for a free electronic copy of GMT Instruction Manual.