Do know that P/N 514487 is for the Hold Down Rod that has the threaded end for the current Hold Down assembly. That Assembly includes the "T" Nut and Washer for use in the Fences with a "T" Track. It can be used on the Mark 5/V 500 original Table System Fence and other Mark models like the Mark 2 or 1960's Mark VII plus the Model 10's by inverting the rod having the threads up. I don't have the part number for the original Rod without the threaded end but it is no longer available anyway. Below is a picture of different Mortising Attachments and their Hold-downs from different eras. The one on the right is the current version with the Threaded Rod and "T" Nut.
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The one on the left is from the Model 10's. It has different size Allen Wrench (3/16" & 1/8") Cap and Set Screws. There was a Goldie painted set and a gray set without the Threaded Rod, Washer and "T" Nut.
If you are going to use the "T" Nut in a "T" Track Fence don't forget the Washer. Without the Washer the "T" Nut will not lock into the track.
