|
||
|
27th May 2013, 10:35 | #21 |
This is my second home
Rover75 and Mreg Corsa. Join Date: Nov 2006
Location: Sumweer onat mote o'dust (Sagin)
Posts: 21,753
Thanks: 341
Thanked 3,660 Times in 2,924 Posts
|
That simplifies it a lot, thanks.
Wiki doesn't help much other than illustrating why I asked: http://en.wikipedia.org/wiki/Screw TC |
27th May 2013, 11:41 | #22 |
Banned
Rover 75 Tourer CDT Connoisseur SE Join Date: Dec 2010
Location: Newport
Posts: 1,906
Thanks: 107
Thanked 299 Times in 206 Posts
|
They are flanged head bolts. Given the softness of the head I would be surprised if the bolt is that hard, but it could have been induction hardened. They are 60mm including the head (I know I should have measured the threaded portion), and as you can see, a good 5mm is non-loaded.
|
27th May 2013, 11:42 | #23 |
Banned
Rover 75 Tourer CDT Connoisseur SE Join Date: Dec 2010
Location: Newport
Posts: 1,906
Thanks: 107
Thanked 299 Times in 206 Posts
|
Sorry, should have uploaded the photo!
|
27th May 2013, 12:03 | #24 |
Loves to post
75 Contemporary SE Mk II 2004 Auto. Sal. CDTi Join Date: Nov 2010
Location: Fareham
Posts: 366
Thanks: 0
Thanked 0 Times in 0 Posts
|
The end of that screw has been specially machined, I wonder why ? Looks part bleed nipple part self tapper - weird, especially at M12. What function is that conical end performing I wonder.
|
27th May 2013, 12:16 | #25 |
Banned
MG ZT+ V6 190 Join Date: Nov 2011
Location: Spalding
Posts: 13,245
Thanks: 369
Thanked 1,196 Times in 818 Posts
|
Looks like it's designed to also locate the part as well as hold it and the end of the bolt is designed to locate properly, to minimise any cross-threading!
|
27th May 2013, 12:39 | #26 |
Loves to post
75 Contemporary SE Mk II 2004 Auto. Sal. CDTi Join Date: Nov 2010
Location: Fareham
Posts: 366
Thanks: 0
Thanked 0 Times in 0 Posts
|
|
27th May 2013, 12:45 | #27 |
Banned
MG ZT+ V6 190 Join Date: Nov 2011
Location: Spalding
Posts: 13,245
Thanks: 369
Thanked 1,196 Times in 818 Posts
|
|
27th May 2013, 13:30 | #28 |
Loves to post
75 Contemporary SE Mk II 2004 Auto. Sal. CDTi Join Date: Nov 2010
Location: Fareham
Posts: 366
Thanks: 0
Thanked 0 Times in 0 Posts
|
Rimmers NLA, Brown and Gammon NLA, X-Part 1 off - and thats all the google results pull up with that part number
I have also found a posting from another forum that shows them NLA in May 2006, and they confirm its M12 fine thread too. Its starting to look like a special run off from a machine shop |
27th May 2013, 14:15 | #29 |
Banned
Rover 75 Tourer CDT Connoisseur SE Join Date: Dec 2010
Location: Newport
Posts: 1,906
Thanks: 107
Thanked 299 Times in 206 Posts
|
If you can find a machine shop that will happily work with 12.9 grade bolts! Although there is no stamping on the head of these so it is possible (unlikely) that these are "normal" steel. I think the end of the thread is designed to clean out the threads as they are removed, like a tap. I doubt if it gives any physical properties to the bolt. Interestingly Rover only recommend a torque load of 100Nm which is not a lot, given the stresses on these bolts. Just going from 8.8 to 12.9 bolts gives a 30% increase in strength, but I just wonder how much stress these bolts need to take?
|
27th May 2013, 14:39 | #30 |
Gets stuck in
Jaguar XE Prestige Join Date: Oct 2010
Location: Coventry
Posts: 540
Thanks: 155
Thanked 109 Times in 101 Posts
|
Hi, I would use these with a suitable washer https://www.spaldingfasteners.co.uk/...olts-grade-129
Regards John |
|
|