'63 Valiant V200 wagon - rare bolt issue
I'm finally getting around to installing my tailgate torsion bar, which I had reproduced to match the shape of a rusty one supplied by @65 Dartman, and tempered to the correct hardness. Inside my tailgate, there were three clamps; the one on the drivers side is bigger and heavier, or course, because it holds down the bent end of the bar, and sees all the action. There were only fragments of the original torsion bar. The middle clamp was lying inside the tailgate, with the bolt missing; the clamp at the other end was still bolted in place. I managed to get the old bolt out, although it was badly rusted; I cleaned it up pretty well with a 1/4-20 die, and now it turns freely, as it does with a 1/4-20 nut.
I got some 1/4-20 bolts of the right length, and attempted to put them in. They don't fit! They start, but - I bent one trying, and snapped the head off another. Fortunately I was able to back it out, and the old bolt still turns in the holes.
I'm persuaded at this point that the old bolt is not 1/4-20 - it's a #12 bolt, or a 12-20. They are rare today, but apparently once used in some applications - and I think this is one of them. A #12 bolt has a 7/32" shank, or 1/32" less than that of a 1/4" bolt. 1/32" is probably enough to account for the trouble I am having.
If I had easy access - or, enough room - I'd tap one of the holes (since the old bolt is serviceable) to 1/4-20. But I don't.
Is my supposition plausible? If so, where do I go to get a 12-20 bolt?
Dan
I'm finally getting around to installing my tailgate torsion bar, which I had reproduced to match the shape of a rusty one supplied by @65 Dartman, and tempered to the correct hardness. Inside my tailgate, there were three clamps; the one on the drivers side is bigger and heavier, or course, because it holds down the bent end of the bar, and sees all the action. There were only fragments of the original torsion bar. The middle clamp was lying inside the tailgate, with the bolt missing; the clamp at the other end was still bolted in place. I managed to get the old bolt out, although it was badly rusted; I cleaned it up pretty well with a 1/4-20 die, and now it turns freely, as it does with a 1/4-20 nut.
I got some 1/4-20 bolts of the right length, and attempted to put them in. They don't fit! They start, but - I bent one trying, and snapped the head off another. Fortunately I was able to back it out, and the old bolt still turns in the holes.
I'm persuaded at this point that the old bolt is not 1/4-20 - it's a #12 bolt, or a 12-20. They are rare today, but apparently once used in some applications - and I think this is one of them. A #12 bolt has a 7/32" shank, or 1/32" less than that of a 1/4" bolt. 1/32" is probably enough to account for the trouble I am having.
If I had easy access - or, enough room - I'd tap one of the holes (since the old bolt is serviceable) to 1/4-20. But I don't.
Is my supposition plausible? If so, where do I go to get a 12-20 bolt?
Dan