I have just made a pair of garden gates in Iroko and I'm intending to use
Sadolin Classic (1 coat) and Sadolin Extra (2 coats) to finish them off.
On reading the small print on both products it states that only
non-ferrous screws nails and fastenings should be used.

I have used some zinc yellow passivated screws on my gates to fix the T&G
facing boards to the gate structure. I would be happy to change the
screws for brass, but can't find any on t'internet. I need 4 x 45mm
countersunk, posidrive preferably. (In a reasonable quantity, say a
couple of dozen!)

At the end of last year I got some brass screws from "Bit of Brass".
www.abitofbrass.co.uk They might have something suitable

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

Thanks for the link. Unfortunately the size of screw I need isn't listed. Really interesting site though!