MCMechE
Mechanical
- Aug 1, 2018
- 1
Heavy Hex Structural Bolt Dimensions allow the bolt to be larger than the ID of the hole or washer of the same nominal size. Interference especially occurs between the radius between the bottom of the bolt head and the bolt shank, resulting in a bolt which does not sit flush against the top of the washer or structure. What is the appropriate action in such case?
For Example:
For a 1" ASTM A490 bolt there is a radius between the shank of the bolt and the bottom of the bolt head. The radius is between .062" - .093". The shank diameter is between .976"-1.022". This means if the shank is 1.022" with a radius on each side of .093", then the ID of the washer would need to be 1.022+.093+.093 = 1.208" at a minimum. The actual ID of an ASTM F436 1" washer is 1.063". Doesn't that mean there can be up to .145" of interference between the washer and radius, and the head of the bolt wont sit flush against the washer?
For Example:
For a 1" ASTM A490 bolt there is a radius between the shank of the bolt and the bottom of the bolt head. The radius is between .062" - .093". The shank diameter is between .976"-1.022". This means if the shank is 1.022" with a radius on each side of .093", then the ID of the washer would need to be 1.022+.093+.093 = 1.208" at a minimum. The actual ID of an ASTM F436 1" washer is 1.063". Doesn't that mean there can be up to .145" of interference between the washer and radius, and the head of the bolt wont sit flush against the washer?
