Size and Thread Type of the Mounting Holes for Bulldog Heavy-Duty Cast Head Coupler BD44150W0317

Question:

The Bulldog A-Frame Trailer Coupler - BD44150W0317 comes with three tapped holes for mounting a trailer jack. What size and thread pitch are the these holes tapped for?

asked by: Don

Expert Reply:

I went out to the warehouse to take some measurements of Bulldog Heavy-Duty Cast Head Coupler # BD44150W0317 for you. I used some digital calipers and found the diameter of the threaded holes is 0.27 inches. It was not all that easy to measure but I believe that there are 12 threads per inch. The threaded holes have a depth of 0.35 inches and I counted 4 or 5 threads (depending on where you start counting) which would be a minimum of 12 threads per inch. The 0.27 and the thread type makes the holes 5/16 fine thread.

expert reply by: Michael H