Go-No Go Gauge & Reamer

[Someoldguy]

I guess it must hurt something to check your measuring tools at more than one place within the range that they were designed to measure. Evidently I've done wrong to pick-up a 1/4" gauge block and see if my mic reads .250. How many just take for granted, and don't bother to check their measuring tools, at all? I'll continue to use that 1" standard, or whatever gauge block, or run them to 'zero', regardless of what the -----anyone on this forum seems to think. Some on these forums can find more ---------- to nit-pic over!

I'm not sure how or why this was/is viewed as nit-picking. I asked a simple question, and received a simple answer.

Sorry if that bothers anyone. Carry on, then!

 

[butchlambert]

I'm not sure how or why this was/is viewed as nit-picking. I asked a simple question, and received a simple answer.

Sorry if that bothers anyone. Carry on, then!

From one old fool to another. More than I did not take your post as posted.
Tote it on!

 

[geo.ulrich]

Yes he could. But calibration is checked at the smallest measurement, correct?
0.0000" for a 0"-1", 1.0000" for a 1"-2", etc. Or so I was taught.

No, Calibration is done through the range of the tool. To expand on no you can not take a .250, .500,.750 gage blocks and correctly calibrate a micrometer. you are checking the pitch at the same point so you need to check at .000, . 330,.520, .730 this way you are checking at different points on thread pitch.....

 

[fguffey]

I guess it must hurt something to check your measuring tools at more than one place within the range that they were designed to measure.

Measuring tools: That is different if we are talking about a dial caliper. I have height gages that have a height of 11 inches. I set them up by wringing different standards/blocks etc. I know, I do not believe I have ever been surrounded with so many people that can find so many reasons for not being able to do something or finding reasons why something will not work. When I stack standards someone wants to claim it will not work because of the lube between the blocks. Anyhow, it bothers them more than it bothers me.

One of my better gages is a Pratt & Whitney, it was an electronic gage that started measuring at .000005", for me that was annoying so I removed the electronics and went with a dial caliper. Point: If checking the accuracy of my micrometers across the complete range bothers other members it bothers them more than it does me.

F. Guffey

 

[shortgrass]

Dial or digital calipers are for "close enough" type work.

 

[fguffey]

Some on these forums can find more ---------- to nit-pic over! Maybe if they'd get off their rear end and actually go do something they'd not have so much 'free' advice to dish out........

They are scared, they are afraid and the worst thing, they are lonely. Getting them to back away from the key board? I took a short trip to the country looking for a 5.7/350 GM engine. I thought I found one for $100.00, the owner claimed he built it, used it for a few months and then changed it out because it used oil. If I could not determine why the engine used oil I would not purchase it. I asked the seller for a feeler gage and then got to the point I could remove a ring from a piston. After removing the ring I placed the ring into the cylinder and straightened it with the piston; I measured the gap at the end of the ring; .030"+. The builder board the engine .030" over standard and then installed standard rings. He did an excellent job of boring and honing the cylinders. I will go back next weak end to get the block with 3 heads that do not match but he also had a 11 file drawer cabinet for sale for $100.00 and three Binks 2 1/2 gallon sprays for $25.00 each, including the built in air operated stir mechanisms.

Why didn't I get the engine? It is easier to get this stuff home a little at a time than bringing it home all at once. There is always a chance if I bring this stuff home a little at a time the wife will not notice.

F. Guffey

 

[butchlambert]

They are scared, they are afraid and the worst thing, they are lonely. Getting them to back away from the key board? I took a short trip to the country looking for a 5.7/350 GM engine. I thought I found one for $100.00, the owner claimed he built it, used it for a few months and then changed it out because it used oil. If I could not determine why the engine used oil I would not purchase it. I asked the seller for a feeler gage and then got to the point I could remove a ring from a piston. After removing the ring I placed the ring into the cylinder and straightened it with the piston; I measured the gap at the end of the ring; .030"+. The builder board the engine .030" over standard and then installed standard rings. He did an excellent job of boring and honing the cylinders. I will go back next weak end to get the block with 3 heads that do not match but he also had a 11 file drawer cabinet for sale for $100.00 and three Binks 2 1/2 gallon sprays for $25.00 each, including the built in air operated stir mechanisms.

Why didn't I get the engine? It is easier to get this stuff home a little at a time than bringing it home all at once. There is always a chance if I bring this stuff home a little at a time the wife will not notice.

F. Guffey

??????, so how did you check your feeler gauges?

 

[geo.ulrich]

well I guess all that I learned working in a gage lab was wrong my mistake. But I did download micrometer calibration procedure page 2 per Navair 17-20 Md-06 per I.S.O. you know the International Standards Organization. If you need anymore help on actual calibration I have a file full its part of U.S. Government procedures...

 

[John11-87]

you are checking the pitch at the same point so you need to check at .000, . 330,.520, .730 this way you are checking at different points on thread pitch.....

The little bit of machining I've done, this is one of the most frustrating aspects of it. In your professional opinion what is the best way to accurately check a OD Thread? From a Precision machining standpoint, I've seen many times the wrong nose radius insert used, and the thread will gauge with go/no go gauges but the minor diameter is incorrect. In gunsmithing I've heard a million times, "your ID thread is to big/small" when I send them a adapter or muzzle device. I've found most of the time the tool used to cut the OD muzzle thread is a HSS tool ground with a center point gauge.

John

 

[geo.ulrich]

The little bit of machining I've done, this is one of the most frustrating aspects of it. In your professional opinion what is the best way to accurately check a OD Thread? From a Precision machining standpoint, I've seen many times the wrong nose radius insert used, and the thread will gauge with go/no go gauges but the minor diameter is incorrect. In gunsmithing I've heard a million times, "your ID thread is to big/small" when I send them a adapter or muzzle device. I've found most of the time the tool used to cut the OD muzzle thread is a HSS tool ground with a center point gauge.

John

John, only metric threads should have a radius on the tip of insert or cutter, Thread mics. are great if you have them or wires but there more of a pain to use. threads should be trunicated which is a fancy name for they should have a flat on both the root and crest of thread. threads should really be gaged at pitch diameter or centerline of form. other thing to remember is tolerance if your id thread is to the small side and od thread is large it will be tight and opposite. really I do not sweat a thread that's alittle loose main thing is to shoulder square.. hope this helps

 

[butchlambert]

I'm sure not in the class with George or a couple others on this forum. I did acquire a thread mic from Gene Bukys for tenon threads. I used to have some of the triangle shaped thread wires. I also have threaded inserts for different tenons. Screw one on as you thread. If it feels good, you won. I bought mine many years ago from Kelblys and from Stiller. They cover several tenons.

 

[John11-87]

John, only metric threads should have a radius on the tip of insert or cutter, Thread mics. are great if you have them or wires but there more of a pain to use. threads should be trunicated which is a fancy name for they should have a flat on both the root and crest of thread. threads should really be gaged at pitch diameter or centerline of form. other thing to remember is tolerance if your id thread is to the small side and od thread is large it will be tight and opposite. really I do not sweat a thread that's alittle loose main thing is to shoulder square.. hope this helps

I understand what you are saying, and I agree, wires are the most accurate way the check thread pitch without a CMM, or optical comparitor of some sort. For gunsmithing a pitch mic is probably good enough, but a thread can pitch correctly and still be no good, for example if the thread insert tip chips. Is there any sure fire way to check accurately with tools besides, go/no go ring gauges, thread wires, or pitch mic, to insure that the thread pitch/minor are in spec? My best trick for checking Minor Diameter is to put to of the same conical ends in a pitch mic, zero it out and take a measurment.

We use inserts for certain threads that are specific to the thread pitch. 4.5, 4, 2.0, 1.5, 1, for metric, and 18 20 and 24 for standard. Those inserts, have a shoulder up top that cuts the flat on the crest of the thread, and work really nice. Offset always runs right at 0 +/- .001. How come only metric threads would require a radi on the insert? My standard Seco thread insert will cut anything from a 8 pitch up to a 40 ( smallest I've ever cut ), the corner on that one a radius cant be seen, maybe .001 or .002. When cutting more coarse threads metric or standard and pipe threads, the inserts we have, have a visible radius.

thanks for the info geo,

John

 

[geo.ulrich]

I understand what you are saying, and I agree, wires are the most accurate way the check thread pitch without a CMM, or optical comparitor of some sort. For gunsmithing a pitch mic is probably good enough, but a thread can pitch correctly and still be no good, for example if the thread insert tip chips. Is there any sure fire way to check accurately with tools besides, go/no go ring gauges, thread wires, or pitch mic, to insure that the thread pitch/minor are in spec? My best trick for checking Minor Diameter is to put to of the same conical ends in a pitch mic, zero it out and take a measurment.

We use inserts for certain threads that are specific to the thread pitch. 4.5, 4, 2.0, 1.5, 1, for metric, and 18 20 and 24 for standard. Those inserts, have a shoulder up top that cuts the flat on the crest of the thread, and work really nice. Offset always runs right at 0 +/- .001. How come only metric threads would require a radi on the insert? My standard Seco thread insert will cut anything from a 8 pitch up to a 40 ( smallest I've ever cut ), the corner on that one a radius cant be seen, maybe .001 or .002. When cutting more coarse threads metric or standard and pipe threads, the inserts we have, have a visible radius.

thanks for the info geo,

John

John, well if insert chips then thread would not have clearance at root of thread , I don't see this as so much of a measuring problem but a machining issue , your tools must be sharp. Metric threads have radius by design probably for strength or shear, weird part is radius is different for internal to external mating threads. I have seen the inserts that cut o.d. to a finish dia. they look to work well, I have not used them. I still just turn to .008 under and single point until I get p.d. correct. Go/no go are about as good as it gets to me, but most places don't have or don't want to buy them. If I had to machine a lot of the same threads I would have some sort of gage whether purchased or made here...