Rasp bar tightness Tx66?

Did rasp bar on MF 7256, no torque figure in workshop manual and originals not especially tight.
Had two options which was find torque figure for 8.8 bolts which were new and replaced with bar or make sure they are FT ( farmer tight etc).
Opted for latter as used impact gun to make up then breaker bar for 1/2” socket set to make sure tight.
Given that most standard spanner’s are the ideal length for a standard bolt torque, using the breaker bar to increase torque slightly was ok. Old man also shocked the bolt when tight before final checking to make sure not hung up on anything.
I am comfortable with this approach as did same for MF36 which then did 10 years with no issue.

Appreciate it is a NH but same principles apply, appreciate work involved removing trunk and piece of mind knowing bolts are correct torque gives but generally bolt torques for a given size should be material and lubricant dependant which many of the agricultural manuals fail to cover. Work in oil industry and difference in tension applied to a bolt with different or no lubricants applied is scary.
 

Farmer Fin

Member
Arable Farmer
Location
Aberdeenshire
Did rasp bar on MF 7256, no torque figure in workshop manual and originals not especially tight.
Had two options which was find torque figure for 8.8 bolts which were new and replaced with bar or make sure they are FT ( farmer tight etc).
Opted for latter as used impact gun to make up then breaker bar for 1/2” socket set to make sure tight.
Given that most standard spanner’s are the ideal length for a standard bolt torque, using the breaker bar to increase torque slightly was ok. Old man also shocked the bolt when tight before final checking to make sure not hung up on anything.
I am comfortable with this approach as did same for MF36 which then did 10 years with no issue.

Appreciate it is a NH but same principles apply, appreciate work involved removing trunk and piece of mind knowing bolts are correct torque gives but generally bolt torques for a given size should be material and lubricant dependant which many of the agricultural manuals fail to cover. Work in oil industry and difference in tension applied to a bolt with different or no lubricants applied is scary.
Thanks. Well today cost me £50. Father had spoken to someone who had done a few who said FT. So we started this morning by putting them on with the impact gun but on a low setting and not overly tight as we planned to then use a bar to tighten. At lunch I though I better check the torque from APH who supplied the bars and they said 100nm. Checked the 3 bars we had put on - up to 130nm. Phoned another mechanic who’s first words were 100nm and then take the bolts out and replace with new. Lesson learned get all the information before you start!

Ours were tight to get off but in hindsight it was probably the coating on the bolts as much as anything else.
 
The joys of impact guns, put more torque in than you realise, our impact gun does something like up to 950Nm (or did when new) and used it on low setting and feathered it in so not getting full whack.

The torque that APH supplied sounds right for a M12 8.8 bolt, your bolts would probably have been ok if they were installed dry as lubricant on threads and nut face makes significant difference to applied tension and thus % proof load applied to bolt.

Screenshot 2021-10-04 at 19.18.23.png
 

balerman

Member
Location
N Devon
I think you are all overthinking this job,did our NH 3 years ago.New bolts come with the blue loctite already on,did ours up with 18 inch Tommy bar and thought no more of it.
 

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Man fined £300 for bonfire-related waste offences

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Written by William Kellett from Agriland

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A man has pleaded guilty at Newtownards Magistrates’ Court to waste offences relating to a bonfire next to the electrical sub-station on the Circular Road in Newtownards, Co. Down.

Gareth Gill (51) of Abbot’s Walk, Newtownards pleaded guilty to two charges under the Waste and Contaminated Land (Northern Ireland) Order 1997, for which he was fined £150 each and ordered to pay a £15 offender’s levy

On June 25, 2018, PSNI officers went to Gill’s yard, where they found a large amount of waste consisting of scrap wood, pallets, carpet and underlay.

Discussion with Northern Ireland Environment Agency (NIEA) officers confirmed the site...
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