Designated by an "SH" at the beginning of the part number, the Heavy Hex Security Locknut is the most commonly ordered series. This nut body pattern has a greater width across the flats and is thicker in its height as compared to a Standard or Finished Hex nut body. Its "beefier" body spreads the load tension of a joint across a larger bearing area theoretically allowing a given joint to withstand greater force than a standard nut body. Heavier nuts tend to be preferred in uses where bolts are going to be loaded to target preloads in excess of 60 - 70% of yield or an extra degree of safety is desired.

They are generally available from stock in Grade 5 and Grade 8* equivalents, Course (UNC) thread sizes 3/8" - 4" Full or Jam/Thin patterns as well as in special custom styles which are thinner in height and have flush or recess mounted inserts.

*For Grade 8 equivalent part numbers, just add a "G8" to the end of the standard part number.