Probably would be ok. I wouldn't do it because I'd be worried about overstressing the threads on those holes. They are not big bolts.
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I made a 12" bar and never had any issues. The reason being is you tighten the bolts down, so you are using the bolts to clamp the bar flat to the IP; the only stress on the bolts is straight in and out(like a lug nut - a loose lug nut will break easily; a tight one won't).
Here are some useful numbers:
1. These bolts are 1/4-20 bolts, going into aluminum, lets
assume 1/4" deep(I think it's longer than that, but...)
2. For a steel socket head cap screw going into aluminum, 1/4 dia, 1/4 depth, use chart E506 at
http://viewmold.com/Products/Techni...ation/STRIPPING STRENGTH OF TAPPED HOLES.html
3. This gives a strength of 160,000lbs/sq-in.
A 1/4-20 bolt has a minor diameter of .187, so plugging that int0 pi-r-squared, we get .0275 sq/in.
4. This gives a clamping load of 4400lbs for a socket head cap screw going 1/4" deep into aluminum. Derate that by 72%, worst case, using a grade 2 bolt... that's still 1250lbs of force there.
5. If the two bolts are 1" apart(I think they are slightly further) and you are levering at 12" away from that bolt(12" lever), you have a mechanical advantage of 12, so ~100lbs of force at the end of said 12" lever.
I Think those bolts are strong enough.
If you are really putting anywhere close to 100lbs on a lever to get that pump to move... you are going to break something, or at least stress those lines a lot.