Mechanical Design, Manufacturing and Engineering Forum
[ Home ] [ Search ] [ Engineering and Design Database ] [ Resume/Job Database ] [ Product and Services Directory ]
[
Engineering, Design and Drafting Store ] [ Engineering Forum ] [ DFM DFA Training and Trainers ] [ GD&T Training GD&T Trainers ] [ Advertise ]
[ POSTING POLICY / RULES ][ Archive#1 ] [ Archive #2 ] [ Archive #3] [ Calculators ] [ Tell A Friend ]
Forum Moderators: randykimball, Administrator

Torque required to develop 1323 N (297#) load
Post Reply   Forum
Posted by: calrgl99

04/22/2005, 08:52:44

Author Profile Mail author Edit
I need to do a tightening test on a battry hold down bar. The bar is held down with 2 M6 nuts. I must apply a load of 1323 N to the top of the battery to verify the amount of deformation that will occur to the battery and bar contact surface.
What is the torque on one nut in Ft.# or In.# required to apply a load of 1323 N (297#) to the top of the battery surface?
Equal resultant torque will be applied to both nuts during test.







Modified by calrgl99 at Fri, Apr 22, 2005, 10:03:08

Post Reply | Recommend | Alert View All   | Next |

Replies to this message


Re: Torque required to develop 1323 N (297#) load
Re: Torque required to develop 1323 N (297#) load -- calrgl99 Post Reply Top of thread Forum
Posted by: Cragyon
Bart
04/22/2005, 13:45:11

Author Profile Mail author Edit
Using the old-fashioned torque force calculator here on engineers Edge /torque.htm.

Assuming each screw has an equal influence on the applied force, I calculate 7.1 in-lbs each screw.







Post Reply | Recommend | Alert Where am I? Original Top of thread | |
Re: Torque required to develop 1323 N (297#) load Smile
Re: Re: Torque required to develop 1323 N (297#) load -- Cragyon Post Reply Top of thread Forum
Posted by: calrgl99

04/25/2005, 10:38:20

Author Profile Mail author Edit
Thank you for the information. I have, and will again review the torque force calculator, but I had our test lab set up a fixture to get actual torque and load values. Fixturing the actual parts and attaching a loadcell to digitally read the load, we determined that the actual load at 1328 N requires an average of 3.8 N*m (2.8 ft. lb.) torque. This test was performed 4 times, and was applied with one screw. The screws (nuts) will have equal influence of applied force when applied for our battery hold down torque test.
Thank you very much for your response.






Post Reply | Recommend | Alert Where am I? Original Top of thread | |
Re: Torque required to develop 1323 N (297#) load Smile
Re: Re: Torque required to develop 1323 N (297#) load -- calrgl99 Post Reply Top of thread Forum
Posted by: Cragyon
Bart
04/25/2005, 13:04:22

Author Profile Mail author Edit
I'm sure you are aware that the calculations associated with torque is, at best only an estimate. Factors, such as lubrication, fastener size, surface roughness, number of times a fastener/thread has been torqued, temperature and dissimular materials can complicate the resultant torque applied force. Also, release or removal torque tends to different than installtion torque, even only a few moments after the torque had been applied.

Torque design should be viewed as just that, an estimate. Fortunately, installation forces are forgiving. For precision control of applied force due to torque, strain gauges or constant force springs may need be considered.







Post Reply | Recommend | Alert Where am I? Original Top of thread

Powered by Engineers Edge

© Copyright 2000 - 2018, by Engineers Edge, LLC All rights reserved.  Disclaimer