No matter how long you work on farm equipment, there are always things to learn. In the past few years I’ve finally learned or understood…
1. A “screw” has threads all the way to the bottom of its head. In parts books, what a farmer would call a ¾” x 3” “bolt” would be listed as a “screw” if its shank was fully threaded. According to engineers, a “bolt” has some portion of its shank without threads.
2. Quality flat washers have a top and bottom. Look carefully at the edges of the hole. If one edge is a sharp right angle and the other has a taper or chamfer, that tapered/chamfered edge should rest against the underside of a bolt’s head. The junction between a bolt’s head and its shank isn’t a sharp right angle, so having a rounded or chamfered edge on the washer prevents stress cracking between the bolt and the washer.
3. How far should a bolt protrude through a nut to obtain maximum strength from the threads? If two threads are protruding beyond the nut, maximum connecting strength has been achieved. So I was told by an engineer at a bolt manufacturing plant.
4. That engineer also assured me that a flange head nut or bolt, properly tightened to recommended torque, holds as well as plain hex-head nut/bolt with a lock washer. Especially if it’s a flange-head nut/bolt with serrations on the underside of the head.
Read more from Dan Anderson:
The New Generation: Not Your Grandfather’s Box Drill
Procuring Farm Machinery Parts: The Big Picture
