bolt length

[macsailor]

Im putting Harken 295 7/8 flat risers on my cam cleats to get less of an angle to make it easier to cleat while singlehandling. I noticed on the mod board that someone else did the same. If someone could let me know what diameter and length of bolts I need, it would be much appreciated. The boats an hour away, and noplace there to buy anything stainless. Thanks in advance...Fair winds