Torque Control 5
No two bolts respond exactly the same to a given torque. There are numerous “real world” complications. Things such things as dirt in a tapped hole, damaged threads, hole misalignment, and numerous other
factors can absorb a large amount of the input torque and will result in a substantial loss in the preload which was determined. Some of the other common variables affecting the K factor may include, but not limited to:
• Hardness of all parts
• Types of materials
• Class of fit
• Plating, thickness and type
• Surface finishes on all parts
• Manufacturing processes, such as cut or rolled thread
• Washers, present or not
• Type of tool used for tightening
• Speed of tightening
• Which is torqued, the nut or the bolt
• The number of times the fastener was used
• The type, amount, condition, method of application, contamination, and temperature of any lubricant used
