I'm perhaps late to the fair with this, but #4 pan-head phillips sheet-metal screws work well in mounting Delta fans on heatsinks. Only 2 are needed for a solid install. Which is good because the sinks are fastened to the card by 2 sprung screws so there are only 2 corners free.
The first job was to put a 40x40x15mm fan on a reflashed LSI 9220-8i card (supposedly it was a used IBM M1015, but it was probably a Chinese counterfeit, and has begun shedding ports). It has a 12mm thick, leaved (not pronged) sink, and the 3/4" length worked well, spreading the leaves slightly as they bit in.
For the replacement card, a new LSI 9207-8i HBA that has a 44x44x15mm pronged sink, 7/8" screws would have worked well, but I couldn't find any locally. So I settled for cutting the tips off 1-inch screws and filing the cut ends to blunt points before installing them. That appeared to work okay, though the prongs are far enough apart that the threads didn't bite very deeply. I might later replace them with #6 screws, tho #6s are a tight fit and must be hand-selected from the bin to fit at all.
For translating to metric sizes, my caliper says the #4 "Everbilt"-brand screws I bought at Home Depot (a large US vendor of building material & similar) are 2.81 mm across the threads. They were made in the PRC of course(!) so there's no guarantee that the next batch will caliper out the same, making it a good idea to buy enough for future use too.
The first job was to put a 40x40x15mm fan on a reflashed LSI 9220-8i card (supposedly it was a used IBM M1015, but it was probably a Chinese counterfeit, and has begun shedding ports). It has a 12mm thick, leaved (not pronged) sink, and the 3/4" length worked well, spreading the leaves slightly as they bit in.
For the replacement card, a new LSI 9207-8i HBA that has a 44x44x15mm pronged sink, 7/8" screws would have worked well, but I couldn't find any locally. So I settled for cutting the tips off 1-inch screws and filing the cut ends to blunt points before installing them. That appeared to work okay, though the prongs are far enough apart that the threads didn't bite very deeply. I might later replace them with #6 screws, tho #6s are a tight fit and must be hand-selected from the bin to fit at all.
For translating to metric sizes, my caliper says the #4 "Everbilt"-brand screws I bought at Home Depot (a large US vendor of building material & similar) are 2.81 mm across the threads. They were made in the PRC of course(!) so there's no guarantee that the next batch will caliper out the same, making it a good idea to buy enough for future use too.
