Just wondering how many of you guys use a thread mic or do you use a ring and plug gauge?
Seems to me thread mic would be the better option.
Seems to me thread mic would be the better option.
Gunsmithing Measuring threads when single point cutting
- Thread starter SSC
- Start date
Re: Measuring threads when single point cutting
"Pee-Dee", AKA, Thread wires on OD stuff.
Plug gauges on ID threads.
"Pee-Dee", AKA, Thread wires on OD stuff.
Plug gauges on ID threads.
Re: Measuring threads when single point cutting
It really depends on what you are doing. Most gunsmiths I know that are fitting a barrel are using the action as the "Go Gage". This is because actions vary from maker to maker and then some have been trued and recut. As an action builder I use plug and ring gages on everything. If I don't have the right gage I use a thread mike on OD threads and on ID threads I make a plug gage to the specs required. I have made many threads and plug gages with just Pee-Dee wires as mentioned by Chad. Working to known dimensions and classes of threads is important if you want parts to always fit together no matter who made them, or when they were made. Some parts where you want a close fit should be a Class 3-A for external threads and a Class 3-B fit for internal threads. Some parts you do not want a close fit and require a looser Class 2-A or 2-B fit. These are real general statements as there are many types of threads and you need to go to a machinist handbook or some other source for all the threads out there. Meteric, Acme, Stub Acme, Buttress, British Whitworth. I have cut many and I am still running into somthing I have never heard of before. Sometimes you just need to wing it and make it fit.
It really depends on what you are doing. Most gunsmiths I know that are fitting a barrel are using the action as the "Go Gage". This is because actions vary from maker to maker and then some have been trued and recut. As an action builder I use plug and ring gages on everything. If I don't have the right gage I use a thread mike on OD threads and on ID threads I make a plug gage to the specs required. I have made many threads and plug gages with just Pee-Dee wires as mentioned by Chad. Working to known dimensions and classes of threads is important if you want parts to always fit together no matter who made them, or when they were made. Some parts where you want a close fit should be a Class 3-A for external threads and a Class 3-B fit for internal threads. Some parts you do not want a close fit and require a looser Class 2-A or 2-B fit. These are real general statements as there are many types of threads and you need to go to a machinist handbook or some other source for all the threads out there. Meteric, Acme, Stub Acme, Buttress, British Whitworth. I have cut many and I am still running into somthing I have never heard of before. Sometimes you just need to wing it and make it fit.
Re: Measuring threads when single point cutting
Like AJ said, use the receiver as the go gauge when fitting a barrel to it. For suppressor threads, use a 3A ring gauge.
If fitting a barrel for a glue in receiver (BR stuff) I use thread mics.
Like AJ said, use the receiver as the go gauge when fitting a barrel to it. For suppressor threads, use a 3A ring gauge.
If fitting a barrel for a glue in receiver (BR stuff) I use thread mics.
