I bought a set of collets for a very small machine i have, but for some reason, the drawbar uses 1/4-20 whitworth thread. A regular 1/4-20 UNC does not fit more than a few turns of the threads into the collets, so i cannot just directly use a 1/4-20 bolt.
Is there a fast way to modify a 1/4-20 bolt into 1/4-20 whitworth? I thought id just be able to run a 1/4-20 whitworth die over a 1/4-20 bolt, and this would remove the material that is the difference between the threadforms. I thought this would work, since the 55 degree thread form should have less metal, and the die should cut into the 1/4-20 UNC bolt somewhat. But this was not the case, perhaps the die i have is worn, but i can freely thread a 1/4-20 UNC bolt thru my 1/4-20 whitworth die. In fact it kind of feels loose in there, which makes no sense to me, i would expect it only to be loose the other way around, if i were to put a whitworth bolt, into a UNC nut for instance.
Of course i could turn the dang thing myself, but due to clearance/reach issues, i would far prefer the end of the bolt to have a hex socket, and this is not a feature i can readily make. In fact right now i dont even have access to a lathe that can thread.
I thought it would be as easy as just chasing the UNC bolt with the whitworth die, and the 5 degrees of extra material would be removed or chased off by the whitworth die.
Does that fact that this did not happen indicate that my die is worn out? it is from an old set from 1986, but its a complete whitworth set i have lying around.
Thank you.
Is there a fast way to modify a 1/4-20 bolt into 1/4-20 whitworth? I thought id just be able to run a 1/4-20 whitworth die over a 1/4-20 bolt, and this would remove the material that is the difference between the threadforms. I thought this would work, since the 55 degree thread form should have less metal, and the die should cut into the 1/4-20 UNC bolt somewhat. But this was not the case, perhaps the die i have is worn, but i can freely thread a 1/4-20 UNC bolt thru my 1/4-20 whitworth die. In fact it kind of feels loose in there, which makes no sense to me, i would expect it only to be loose the other way around, if i were to put a whitworth bolt, into a UNC nut for instance.
Of course i could turn the dang thing myself, but due to clearance/reach issues, i would far prefer the end of the bolt to have a hex socket, and this is not a feature i can readily make. In fact right now i dont even have access to a lathe that can thread.
I thought it would be as easy as just chasing the UNC bolt with the whitworth die, and the 5 degrees of extra material would be removed or chased off by the whitworth die.
Does that fact that this did not happen indicate that my die is worn out? it is from an old set from 1986, but its a complete whitworth set i have lying around.
Thank you.
