Metric Hex Jam Nuts

Hex Jam Nuts (Metric) are identical to Finished Hex Nuts in all aspects except one:  thickness.  Hex Jam Nuts are approximately 30% thinner than standard Finished Hex Nuts.  This dimensional difference gives them a distinct advantage in low clearance applications.  However, the main utilization of Hex Jam Nuts is in the practice of the 2-nut locking system.  The recommended method is to place a Jam Nut on the bolt adjacent to the joint and tighten it to approximately 25-50% of its recommended torque.  Then, a 2^nd nut --  usually a Finished Hex Nut – is placed on the bolt next to the Jam Nut.  The Hex Jam Nut is held in position while the 2^nd nut is tightened to full torque value.  As the 2 nuts become tightened against each other, a force is created between the bolt and the 2 nuts, thereby “jamming” them together and preventing the possibility of the nuts loosening off the bolt.  Hence the term Jam Nut.
Hex Jam Nuts (Metric) are available in a wide variety of sizes, materials and coatings. 

Call Empire Bolt & Screw or send us a Request for Quote on your Hex Jam Nut (Metric) needs today.