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During the last couple of days I have been asked about better fixings for the marine industry. Particularly to get rid of the horrible stains which can be seen even when 316 marine grade stainless has been used.
What is happening is people are now buying poor quality fixings (without Knowing it of course), this is not the metal composition where the problem exists but in the actual machining tolerance. What does and frequently happen is as these fixings are screwed together they Gall and this removes the protective layer from them and leaves them venerable to attack, Hence the horrible stains that can be seen.
How many people on here have screwed a stainless steel fixing together and been unable to remove it and it has sheared, also just look at the cut of the threads and see how rough it is and not finished well at all?
What can be done to correct this, we actually buy better quality fixings and we can also up the grade of fixings, these will of course be 3 times more expensive but if you think about it how much does a boat actually take in fixings? so if you buy all your fixings for £50 then £150 and you shouldn't ever see a stain again.
The next grade up from 316 Is 317 which has an increased Molybdenum content which aids in Pitting corrosion and in sea water conditions. then again we can up the grade again to a duplex Stainless steel (UNS 31803) and again this has an even higher Molybdenum content and serves even better. Both these grades compare on price and both would be about 3 times more expensive than standard 316 fixings. Please note prices are not taken from cheap Ebay prices which are in the fixings world the dregs of the earth. Even better grades can be purchased but the costs will rocket!
There is a company in the UK which supplies these has a great website and will do small quantities.
Special Fasteners | Non Standard Fasteners | Fastener Manufacturer
I hope this helps anyone doing a boat up.
Cheers
ETEC
What is happening is people are now buying poor quality fixings (without Knowing it of course), this is not the metal composition where the problem exists but in the actual machining tolerance. What does and frequently happen is as these fixings are screwed together they Gall and this removes the protective layer from them and leaves them venerable to attack, Hence the horrible stains that can be seen.
How many people on here have screwed a stainless steel fixing together and been unable to remove it and it has sheared, also just look at the cut of the threads and see how rough it is and not finished well at all?
What can be done to correct this, we actually buy better quality fixings and we can also up the grade of fixings, these will of course be 3 times more expensive but if you think about it how much does a boat actually take in fixings? so if you buy all your fixings for £50 then £150 and you shouldn't ever see a stain again.
The next grade up from 316 Is 317 which has an increased Molybdenum content which aids in Pitting corrosion and in sea water conditions. then again we can up the grade again to a duplex Stainless steel (UNS 31803) and again this has an even higher Molybdenum content and serves even better. Both these grades compare on price and both would be about 3 times more expensive than standard 316 fixings. Please note prices are not taken from cheap Ebay prices which are in the fixings world the dregs of the earth. Even better grades can be purchased but the costs will rocket!
There is a company in the UK which supplies these has a great website and will do small quantities.
Special Fasteners | Non Standard Fasteners | Fastener Manufacturer
I hope this helps anyone doing a boat up.
Cheers
ETEC
