This is a video of the 18 inch dumbbell handles sold by newyorkbarbell. They are very solid and well built. They should hold 120 lbs of 10 lb one inch weight plates. If you watch the video to the end you will see how you can likely get these to hold 140 lbs.
Now sold on Amazon: http://amzn.to/2a0hBB5 (it’s a note of caution that the cap 1″ plates won’t fit on these handles).