There are things called Banjo bolts for use in the brake systems of motor cycles that come in aluminium M10 with a pitch of 1.0mm and the "double" banjo bolts MAY be just about long enough, if I can do without my washer (using Kontact's method of straightening). Banjo bolts come pre-drilled both down the centre and from the side, so may already be sufficiently sacrificial!

I am asking about their length.