honolulujoe
Well-Known Member
well its years since I did any chemistry but isn't it the hydrogen ion that confers acidity?
bluedog333
Well-Known Member
I've always used a homemade electrolysis bucket for cleaning up non-critical parts and nuts and bolts. It works a treat, but I know that the 'new metal' is more porous than before - so has to be treated quickly to prevent further rust developing. I've assumed the more porous parts were always going to be weaker which is why I've only done it for non-critical stuff.
I have to admit I don't know if this is the same reasoning behind acid-cleaning parts, but thought it was worth mentioning the "electrolysis bucket" for those that are interested in de-rusting bits and bobs!
I have to admit I don't know if this is the same reasoning behind acid-cleaning parts, but thought it was worth mentioning the "electrolysis bucket" for those that are interested in de-rusting bits and bobs!
cooltide
sheep fancier
All very interesting and some of it over my head. I always assumed a2 stainless was at least on a par with 8.8gr and a4 stronger.
The problem I have found with stainless fasteners is that they can lock up completely with thread damage.
Can one of you nutty professors explain why anything bolted to a bridge deck must be a4/80 stainless and austenetic?
The problem I have found with stainless fasteners is that they can lock up completely with thread damage.
Can one of you nutty professors explain why anything bolted to a bridge deck must be a4/80 stainless and austenetic?
cooltide
sheep fancier
I meant highways bridge decks
And you don't use a compass to help you put it in the right place? But to answer now that I know what you mean - just because stainless fasteners may not be as strong as carbon steels doesn't mean that you can't use them, you just need more bolt area. If you're designing from scratch that's easy to arrange, and in an environment where corrosion could cause a fastener to fail it's a good insurance policy. The difference between a car and a bridge is that the latter is probably designed to last a hundred years. Whereas a Defender...
cooltide
sheep fancier
http://www.westfieldfasteners.co.uk/Ref_Strength_Spec.html
Found this.
So unless I'm missing something, if you replace your land rover nuts and bolts with the commonly available A2/70 (304 grade) stainless steel, the tensile strength will be 12.5% less and the yield strength (deformation) will be 30% less than the most common en8 / 8.8 grade mild steel bolts.
A4/80 (316 grade) seems to be more or less equal, the 80 designation and en8 both meaning 800MPa tensile strength
Found this.
So unless I'm missing something, if you replace your land rover nuts and bolts with the commonly available A2/70 (304 grade) stainless steel, the tensile strength will be 12.5% less and the yield strength (deformation) will be 30% less than the most common en8 / 8.8 grade mild steel bolts.
A4/80 (316 grade) seems to be more or less equal, the 80 designation and en8 both meaning 800MPa tensile strength
Cooltide, I'm not a metallurgist, and I think that's what we need here, but two reasons not to use stainless are that it is susceptible to galling (which I've seen on boats plenty of times) and the fact that stainless is a bit of a misnomer. It will rust like any steel where Oxygen can't get to it readily, so although it may be pretty externally, behind the scenes all may not be well.
My experience on boats is that we often throw away s/s stuff, from bolts to entire bottle screw rigging terminals (expensive) due to galling and rust, and although it's an environment where it's all accelerated it has put me off ever using even the strong stuff on a car.
My experience on boats is that we often throw away s/s stuff, from bolts to entire bottle screw rigging terminals (expensive) due to galling and rust, and although it's an environment where it's all accelerated it has put me off ever using even the strong stuff on a car.
You didn't comment when I mentioned the bright side, so I'm not giving you points for that one either.
cooltide
sheep fancier
http://www.bssa.org.uk/50-grades-of-stainless-steel.php
Interesting read bordering on a have I got news for you magazine feature
Interesting read bordering on a have I got news for you magazine feature
