HI LO Set Masters for Thread Rings - Calibration Procedure

[kgriff]

I'm sure there is someone out there that is an expert.
The guy that calibrated all of our thread rings for many years is no longer with the company. I've been trying to redistribute the workload between the rest of us so we can maintain some degree of customer service. However, I've run into some issues with methods that have been employed in the past. One of the questionable methods is the thread ring checking/setting. We have a large quantity of adjustable thread rings, and HI LO set plugs for most ring sizes. I've talked to one of the manufacturer's of HI LO set plugs and know what they say, but I'd like an impartial opinion or two.
Can anyone tell me how they use HI LO set plugs? If possible, could you post or email your procedure to me?

 

[Umang Vidyarthi]

Re: HI LO Thread setting plugs

Hi kgriff. Welcome to the cove

Apparently you are talking about in-house calibration for Thread plug gages. We use Go/No go TPGs, while you have refered to Hi/Lo. Are we talking about the same thing, or is it different?

In the meanwhile have a look here for Gage Calibration.

Umang

 

[kgriff]

Re: HI LO Thread Ring Setting Plugs - Calibration Procedure

Actually, I need to reword the title of the post. I'm actually referring to HI LO set masters for thread rings.
I've found some conflicting information regarding the proper use of these plugs, and I'm looking for input as to how other people use them.

 

[MACIEKM]

Re: HI LO Thread Ring Setting Plugs - Calibration Procedure

Hello

Please correct me if i am wrong but i think you are refering to truncated thread setting plug gages. If so, it is very crucial (if you decide to calibrate them in house) to use proper equipment as in good thread meauring wires, good outside indicating micrometer or even supermic. Personaly i would sugest to calibrate those by a certified lab, due to a fact that those masters are setting your threaded ring gages and those are dispositioning your product.

As for the procedure this is what i would think is crucial to be checked

Go member
1.truncated major dia. 2x
2.full portion major dia. 2x
3.pitch dia. at least if 4 places.
4.thread angle
Same goes for NO GO member.

Hope this helps you a bit.

 

[kgriff]

Re: HI LO Thread Ring Setting Plugs

I'm actually referring to what are called Hilo thread setting plugs, not truncated. We have approximately 400 adjustable thread rings, in sizes from 0-80 to 9"-16, along with master plugs for all sizes. We currently have a mix of truncated and Hilo set plugs. I'm looking at moving totally to Hilo, and away from truncated. The Hilo should give a more consistant result, regardless of which cal tech sets/checks the ring. However, as I stated in an earlier post, I've seen conflicting information regarding the use of Hilo set plugs.
Since I am not a thread expert (though I am learning) I'm looking for help from the thread experts that have used Hilo plugs.

 

[Umang Vidyarthi]

Re: HI LO Thread Ring Setting Plugs

I'm actually referring to what are called Hilo thread setting plugs, not truncated. We have approximately 400 adjustable thread rings, in sizes from 0-80 to 9"-16, along with master plugs for all sizes. We currently have a mix of truncated and Hilo set plugs. I'm looking at moving totally to Hilo, and away from truncated. The Hilo should give a more consistant result, regardless of which cal tech sets/checks the ring. However, as I stated in an earlier post, I've seen conflicting information regarding the use of Hilo set plugs.
Since I am not a thread expert (though I am learning) I'm looking for help from the thread experts that have used Hilo plugs.

To the best of my understanding, you are talking about thread setting plug gauges with HILO trademark. A good idea would be to contact the manufacturer. There are many thread experts on the cove, who will be able to help you wrt calibration process. One excellent expert on 'Threads' is Gordon Clarke, who has helped me a lot on threads.

Good luck

Umang

 

[DietCokeofEvil]

Re: HI LO Thread Ring Setting Plugs - Calibration Procedure

I'm somewhat familiar with using Hi-Lo thread set plugs for calibrating thread rings. We use standard truncated setting plugs here, but I have used Hi-Lo's in the past when supplied by a customer.

If you are using a Hi-Lo set plug to check a thread ring, the ring should freely spin onto the full form portion and come to a dead stop at the truncated. In some ways, it takes out the guesswork when it comes to "feel", since its a rather black and white calibration. I've heard some people say that Hi-Lo gages are better than truncated, but I think that is a matter of opinion. I prefer to have more knowledge of how well a thread ring fits onto a set plug, but thats me.

I agree with the PP about calibration of hi-lo gages if you want to do those in house- you need really good wires and a good supermic or accurate OD mic- the tolerance is a bit tighter than a standard set plug. Hope this helps.

 

[bobhall]

Re: HI LO Thread Ring Setting Plugs - Calibration Procedure

The way I use the HI/LO type thread ring set plug is as follows

The feel on front section should be snug but not tight, and the ring should not go on the rear section of the plug, if it does then the ring needs to adjusted or replaced. This is for the HI/LO Type only, not a Standard Setting Plug.

Hope this helps, and I hope I'm correct.

 

[johannajamison]

Hi-Lo Set Plug Gages are used for setting adjustable GO and NOGO ring gages. The pitch diameter is different for the truncated and full form threads. The setting is correct when the adjustable ring gage can be threaded only onto the full form (LO) portion, but not more than 1½ turns on the truncated (HI) portion.

I also have a question for a plug master. I am interested in the specs for pitch diameter for the Lower Limit for the HI (truncated) portion of the NOGO side of the gage. Will the lower limit be the Nominal value for the NOGO or will it be the Nominal + the Ring Tolerance? Also, can you please help me locate the place in the ANSI/ASME B1.2 where it has this information? I cannot find any information about HI/LO gages in my document.

 

[johannajamison]

OK, I'm not sure if anyone else is interested in HI/LO thread setting plug gages but here is what I have discovered so far. The HI/LO thread setting plug gage is different from regular thread setting plug gages because the pitch diameter is different for the truncated and full form threads. This is because, when you are setting the ring gage, the ring gage is not supposed to go more than 1 1/2 turns on the truncated portion. Therefore the nominal pitch diameter is different for the truncated and full form threads! So why is there only one nominal value on the NOGO side? The world may never know...