What minimum stick-through is required for high-strength bolts?
None. As defined in the 2004 RCSC Section 2.3.2, “The bolt length used shall be such that the end of the bolt extends beyond or is at least flush with the outer face of the nut when properly installed.” Some contract documents include a stick-through requirement (minimum protrusion of the bolt point beyond the nut). However, because the threaded length for any given bolt diameter is constant regardless of the bolt length, a stick-through requirement (which may require a longer bolt) increases the risk of jamming the nut on the thread run-out[1]. Because a stick-through requirement does not enhance the performance of the bolt, its specification is discouraged. Note that there is no specified maximum limitation on bolt stick-through. However, in order to properly tension high-strength bolts, sufficient thread must be available. The use of additional flat washers under the head and/or nut is a common solution when there is a risk of jamming the nut on the thread run-out. Multiple washers
