Well, I think I probably over-simplified my original post. There is an ACME thread on a separate piece that threads on to the barrel. This piece allows the barrel to be mated to the receiver. The threads that mate this separate piece to the barrel are the wierd ones outlined in my original...
Ok, thanks btrueblood. The part in question is a quick change barrel for a machine gun, which has its origins in the 1930s. Perhaps I should be looking at some older standards?
btrueblood: The 25.6 appears to be in mm, while the 15 appears to be turns per inch. There is a note on the drawing (and many drawings that I work with) that all screw threads are represented in inches. I have confirmed that 25.6 is the major diameter and the 15 represents the turns per inch...
KENAT: Thank you. Yes, I am working off of an old drawing that specifies a "25.6-15" thread. And I just had the bright idea of actually measuring the major diameter of the part that has been sitting in front of me for months - it measures 1.004, so maybe I am just an idiot.
Mike: No one is making a tap or die for us. I am making drawings based off of incomplete information.
Ornerynorsk: I found this:
http://www.gomog.com/allmorgan/whitworth.html
Scroll down to the bottom, and there is a "re-naming" of sorts that allows easy conversion in one's head between...
A 25.6-15 Special Form External Left Hand thread. The 25.6 is in millimeters, which as I understand it a 1" thread. It is simply called out as 25.6 instead of 25.4 to make the conversion easier. So basically, I have a 1"-15 left hand thread. My question is: does anyone have any dimensions...
Duwe: I think I understand what you mean now. Thank you.
unclesyd: Thanks for the links - I was actually wondering how to check true position of a pitch diameter. The pdf and last link you provided looks like a solution.
I appreciate all the responses guys, thank you.
Mike, this thread clocking is for the quick-change barrel on a machine gun, so both of our applications relate to weaponry. The ball idea is a definite possibility - I will have to float that idea to a gauge-maker.
Thanks for your response.
Thanks redpicker. I've drawn up some gauge concepts, but I think gauge R&R dictates that the measuring device is supposed to have something like 1/4 of the resolution of the tolerance on the dimension to be measured. I don't think a tolerance of +/-.00016 is possible for a gauge. It might not...
...also known as thread "clocking?" It is a gauge point on the thread surface lying on a plane coincident to the thread axis. It is dimensioned off of the thread axis by means of a basic dimension. It is also dimensioned (and toleranced) off the the perpedicular surface that the threaded hole...
swall:
Rectangular bars or round bars would both be options. I'm not sure how the the 2 different hardnesses would be attained.
Out of curiosity, how did you determine that 5160 or 4150 would work?
Thanks,
Bill
swall:
The part is about 7" long and 1/2" tall. For most of its length it is .200" thick, with the front 1" being .600" thick. So, it is a long, skinny part.
The front 1-1/2" gets through-hardened to around 55 Rockwell C. The remaining 5-1/2" gets through-hardened to around 45 Rockwell C...
Hey guys/girls,
I'm having trouble procuring 8650 steel for an item that my company makes, which is a very high-stress part. Not being terribly knowledgeable about materials, is there a suitable replacement for this material? I would prefer to err on the side of caution and substitute a...
itsmoked: Yeah, sorry! I know some very, very basic electrical stuff, but this was out of my league. The other guy I worked with discovered the ramming solution.
Thanks, old field guy. I'll have to keep that in mind for the future.
Well, we go the thing to work. A single 9V battery appears to be able to actuate the part as long as it is allowed to "ram" the part - with a little gap (about 0.1 inch), the plunger can build up enough speed to hit the part and actuate it, instead of attempting to gently accelerate it.
We...
