Nut & Spring Washer or Nyloc Nut?

Nut & Spring Washer or Nyloc Nut?

Author
Discussion

texaxile

3,290 posts

150 months

Friday 6th January 2017
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When restored my Lancer Turbo, anything that had spring washers and nuts were replaced with nylocs, even though it went against what was originally in situe (which was put there in the early 80's).

My one mistake was considering using Stainless Steel bolts for the suspension rebuild, I was reliably informed that they have less tensile strength than regular steel and not adviseable to use them.

E-bmw

9,219 posts

152 months

Friday 6th January 2017
quotequote all
Sadly, you were either mis-informed or rather not told the full story.

Bolts are graded by tensile strength unless they are cheap ungraded stuff, which you should never use in such a strength critical area.

ie. A stainless 10mm 8.8 bolt has the same tensile strength as a carbon steel 10mm 8.8 bolt.

Where stainless fares less well is under heat cycles as in when used on an exhaust, they very readily seize up, even when copaslipped.

texaxile

3,290 posts

150 months

Friday 6th January 2017
quotequote all
Yep, I went with regular bolts sourced from Mitsubishi because I wasn't sure what ones to use if I were going to use stainless. To see the amount of wear in a 32 year old suspension bolt was surprising!.

Nylocs were the better choice elsewhere though.

anonymous-user

54 months

Saturday 7th January 2017
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I've always been under the impression that stainless bolts for suspension are a total no-no due to them being more likely to fracture under stress, whereas "normal" bolts will bend first?

Both my kitcars have used Nylocs throughout , and I've never seen any of them loosen or fail.

Edit: upon reading up a bit it seems that stainless is more susceptible to fatigue caused by cyclic stress, so if that's correct then it would put me off using them on suspension fixings.

Edited by anonymous-user on Saturday 7th January 11:27

PhillipM

6,520 posts

189 months

Sunday 8th January 2017
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Don't bother with spring washers unless it's for a fastening against a soft/plastic panel, etc, where the bolt isn't torqued anywhere near it's capacity, they're useless under proper loads.

Buy some K-nuts for the exhaust, or use Nordlock washers under normal nuts.

PhillipM

6,520 posts

189 months

Sunday 8th January 2017
quotequote all
E-bmw said:
Sadly, you were either mis-informed or rather not told the full story.

Bolts are graded by tensile strength unless they are cheap ungraded stuff, which you should never use in such a strength critical area.

ie. A stainless 10mm 8.8 bolt has the same tensile strength as a carbon steel 10mm 8.8 bolt.

Where stainless fares less well is under heat cycles as in when used on an exhaust, they very readily seize up, even when copaslipped.
You generally don't get stainless 8.8/10.9/12.9 bolts off the shelf however, they're usually just rated A2/A4 or A4-80 if you're lucky, all of which are quite soft.

Mr2Mike

20,143 posts

255 months

Monday 9th January 2017
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PhillipM said:
You generally don't get stainless 8.8/10.9/12.9 bolts off the shelf however, they're usually just rated A2/A4 or A4-80 if you're lucky, all of which are quite soft.
thumbup An A4-80 is close to, but slightly weaker in tensile and yield strength than an 8.8. A2-70 is weaker again, though still far better than the unmarked cheese fasteners you can buy in B&Q etc.