What is drag torque for a self-locking nut?
Free running, prevailing, or friction drag torque is the amount of torque it takes to turn the nut on the threads. This value will be very small for a plain nut and somewhat higher for a self-locking nut. Regardless of the number, this torque value must be added to the desired torque to achieve final torque.
How do you torque a self-locking nut?
B. When torquing a self-locking nut, the nut should be run down on the threads of the bolt until the nut almost contacts the mating surface. The amount of torque required to run the nut down (friction drag torque) should be measured and added to the amount of torque specified for the fastener.
Do lock nuts need to be torqued?
By definition, “Prevailing-torque locking fasteners have a self-contained feature which creates frictional interference between the threads of the mating components.” Consequently, unlike free spinning lock nuts, there is a resistance to rotation during both assembly and disassembly requiring them to be wrenched; that …
What is a prevailing lock nut?
A locknut, also known as a lock nut, locking nut, self-locking nut, prevailing torque nut, stiff nut or elastic stop nut, is a nut that resists loosening under vibrations and torque.
How much run on torque does a self locking nut have?
Nut (A) is a self locking nut with a run-on torque of 75 inlbs. Run-on torque has been established using a dial indicating torque wrench with bolt (B) fully extended through Nut (A). Question 1: Will the 75 inlbs of run-on torque be added to the required torque of 1000 inlbs for a total applied torque of 1075 inlbs?
What kind of torque is needed to tighten a fastener?
That torque simply resists rotation of the nut on the bolt and does nothing to increase the clamping load. If self locking nuts or bolts are used, the correct procedure is to measure this torque using a beam type or dial type torque wrench while the nut is rotating. Add that amount of torque to the torque needed to properly tighten the fastener.
What are the dimensions of self locking fasteners?
All dimensions are in inches. All dimensions are in millimeters. CFN – 440 – 1 ZI Finish Code PART NUMBER DESIGNATION Type Thread Code Shank Code * PEM Trademark. D E C A T Nylon locking element (Blue identifier* for unified fasteners / black identifies metric fasteners) Clinching profile may vary. SELF-LOCK ASEERS
How much torque do I need for a screw?
Class 12.9 ISO Metric Coarse Pitch Bolts & Screws. Bolt Tension Recommended Corresponding to Assembly 65% of Proof Load Torque kN Nm 3.17 1.9 5.54 4.4 8.97 8.9 12.7 15 23.1 37 36.6 73 53.2 128 72.8 203 98.8 316 121 436 155 620 191 840 222 1066 289 1561 354 2124 437 2884 515 3708.
Nut (A) is a self locking nut with a run-on torque of 75 inlbs. Run-on torque has been established using a dial indicating torque wrench with bolt (B) fully extended through Nut (A). Question 1: Will the 75 inlbs of run-on torque be added to the required torque of 1000 inlbs for a total applied torque of 1075 inlbs?
What is the grade of torque lock nut clamp?
The prevailing torque lock nut clamp loads are listed at 75% of the proof loads specified for the appropriate grade bolt: Grade C – SAE J429 Grade 8, FNL Grade 9 – FNL Grade 9 bolt, Grade F – SAE J429 Grade 5, Grade G – SAE J429 Grade 8.
What are torque specifications for SAE and metric fasteners?
Service Manual Supplement July 2016 Fastener Torque Specifications 4 SAE and Metric Fastener Torque Specifications SAE Plain and Zinc Plated Hex and Socket Head Cap Screws TORQUE CHART – SAE PLAIN AND ZINC PLATED HEX HEAD AND SOCKET HEAD CAP SCREWS Grade 2 or 5 hex head with Grade A nut Grade 5 hex head with Grade 5 or higher nut DRY LUBED DRY
That torque simply resists rotation of the nut on the bolt and does nothing to increase the clamping load. If self locking nuts or bolts are used, the correct procedure is to measure this torque using a beam type or dial type torque wrench while the nut is rotating. Add that amount of torque to the torque needed to properly tighten the fastener.