Is this bolt suitable?
 

Due to the tempreture fluctuation of hot and cold on an exhaust so close to the engine is this bolt ok for holing the downpipe/silencer to the manifold?

https://www.allfix.co.uk/products/ht-high-tensile-bolt-steel-zinc-plated-metric/HTB0ZCM100X0070

they do a 75mm long bolt. I've been advised to use a brass nut as it wont seize onto the bolt. Will the above bolt be ok with the heat fluctuation?

macafee2

I wouldn't worry about 'heat fluctuation' quite honestly. The most relevant thing is to use something that will unscrew again in five years' time. I use basic A2 stainless steel nuts and bolts on the exhaust system, including the manifold studs (which get hotter than the rest). I've never, ever had a problem.


TC

No, above 60C the zinc undergoes a polarity reversal and becomes anodic to the steel.
This essentially means that rather than the zinc corroding to protect the steel, the steel rusts to protect the zinc - not what you want.

Either unplated steel bolts or stainless are the way to go here.

That price list seems odd-------------:shrug:

1 - 10 £23.99 (exc VAT) 11 - 25 £27.86 (exc VAT) 26 - 50 £20.12 (exc VAT) 51 - 100 £16.25 (exc VAT) 101 or more £14.71 (exc VAT)

They come in packs of 100. so 1-10 packs of 100 are £23.99 per pack, buy 11-25 packs they are 27.86 per pack and so on.

I asked about the price not realising they were for packs of 100 but they do them singerly (new word) and are only about 50p each. Also got them to use Royal Mail instead of UPS as UPS was about £8 delivery but my items are less then half of that

worth keeping a note of this place for nuts and bolts in the feature.

macafee2