[golfguru]

If you have a shaft at home sitting about doing nothing, clamp the butt end of it in a vise and the skinny end of the shaft wrap a few layers of lead tape as evenly as possible around it to weight the head end. I know this is not perfect as we use a proper weight but you will get the idea. Now "ping" the shaft and watch it oscillate. It will probably wobble all over the place. Now just clamp it again 90 degrees to the original orientation. Wobble again. Keep doing that until the shaft wobble straight up and down as it slows down. Now you have found your "spine" orientation. Scarily this is present in both steels and graphite shafts. If you have a spine stress tester, you can find which side of the spine is the stiffer line still.

People with educated hands have better feel. SST Puring is the ultimate in spine finding and a robot swinger has massive differences in the impact decals from hitting tests between unspined and spined shafts.