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Tricone Bits Shelf Life.
31 January 2019
Due to the war in Yemen, the Drilling Operation was suspended in April 2015; as result of that,  we have a good amount of 17.1/2", 12.1/4", 8.1/2" and 6" tricone bits (major brands) in the warehouse, most of them were purchased between 2010 and 2015. I am looking for comments and recommendations regarding the use of these bits exceeding the published manufacture's shelf life. I am aware of the potential risks published by manufactures, however, I would like to have experience based comments and recommendations from the community.
Most of these bits were the latest generation at the time with features to drill tough and abrasive formations 
2 answer(s)
Total Posts: 119
Join Date: 05/03/08
Hello Fernando,

I would approach the manufacturers themselves and see what they say.

Of course, they have the potential to be a little biased, in that they also want to sell you a new product!

However, you could also ask some of the independent bit specialists that are around (Aurora in ABZ is one that springs to mind).

The rule of thumb used to be that they wouldn't recommend running any rock bit that was more than 3 years old, as you don't know what has happened to the seals, or the bearings could have developed small 'flat spots' if they have been stored upright for that period of time.

However, that was from several years ago and the recommendation may have changed since then.

I would be very wary about running any of these, given that they are at least four years old.

It only takes one to loose a cone prematurely to offset the savings made in not bringing in new ones.

In addition, advances in seal, bearing and cutter technology over the last few years may have made them obsolete in any case.

Best Regards

Total Posts: 2
Join Date: 06/02/18
Were it me--I would try to put them in a preservative such as Cosmoline. Below is the generic description of it. They would outlast our lifetime then.

Cosmoline is the genericized trademark for a common class of brown wax-like petroleum-based rust inhibitors, typically conforming to United States Military Standard MIL-C-11796C Class 3. They are viscous when freshly applied, have a slight fluorescence, and solidify over time and exposure to air.
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