drill jug for drilling holes in washers

[piper184]

Also different grades of washers have different Id's and OD's, washers also have a top and a bottom when installing. On softer lower grade s this will be noted by the rounded edges on 1 side and sharp edges on the other, for hardened or machined washers the top is denoted by a slightly larger bevel on the ID, these rounded or beveled sides should always be installed next to the bolt heads, this is to lesson the possibility of creating a pinch moment with the fillet radius of the bolt head which could result in a stress fracture of the bolt. the hole Id of washers are larger than the bolt diameters for much the same reason.

Thanks for the explanation Frank! I always just figured the lower grade washers were shaped that way because they were punched but not ground. The low grade washers always irk me that the center hole is nearly large enough for the next size bolt. Sometimes you need that "slop" but usually it just diminishes the effectiveness of the washer.

[Frank S]

Thanks for the explanation Frank! I always just figured the lower grade washers were shaped that way because they were punched but not ground. The low grade washers always irk me that the center hole is nearly large enough for the next size bolt. Sometimes you need that "slop" but usually it just diminishes the effectiveness of the washer.

If you take a look an any structural engineering books there will be a whole chapter on minimum and maximum hole tolerances for fasteners with and without washers and specifications for the types and thickness of washers suggested for drilled or burned holes
For most of my purpose's stamped steel washers are nothing more than a space filler or used as a cushion