We are currently using another method of determining true position of tapped holes with our CMM. Why should we switch to JO-PLUGS®?

Other methods such as using a screw thread, gage pin, or steel ball do not reference the pitch diameter of the thread as specified in ANSI/ASME Y14.5M, 2015 (R’99). JO-PLUGS® offer repeatable and reproducible results in an effective and time-saving manner.

We are using another type of center-line location gage. Why should we switch to Precision JO-PLUGS®?

There are a few companies that offer threaded hole location gages in a variety of styles. The quick answer to this question is quality and service at a competitive price. Spence Industries, Inc. specializes in the manufacture of tapped hole location gages.

The JO-PLUG® tapped hole location gage solid thread form is preferred to split or flex- plugs. Flex-plugs cannot be calibrated for pitch diameter after the thread is split because of the “flex” which cannot be using the three-wire method   Think about it. They’re calibrated before the thread is split. These flex plugs rest on internal thread flanks and do not reference the pitch diameter, and are subject to material fatigue – sometimes referred to as “liquid threads.”
 

Another true position gage is manufactured to determine true position at the surface of the work-piece being inspected. Although offering a solid thread form, this style does not offer much of a projected tolerance zone. Many very popular smaller thread sizes, (#10 or 5mm and smaller), are very small and are not user friendly.

Center-line location gages with mechanical steel balls which expand are subject to failure if not kept perfectly clean. Price on this style could be a prohibitive factor.

JO-PLUGS® utilize a seating surface and upward pressure on the thread flanks to center the JO-PLUG®. Doesn’t this pressure make the JO-PLUG® shift to one side as the gage is threaded into the internal hole?

No. Not to someone who understands how threads function. Spiral rotation involving internal and external threads with very precise internal and external pitch diameters as well as lead and trail angles on the thread flanks is significant. Finger-tight insertion using knurled diameter centers the JO-PLUG® as slight upward pressure is applied. Repeatability and reproducibility studies conducted by a National Laboratory rank JO-PLUGS® # 1 for least amount of standard deviation.

Your price list does not have the thread size we would like to purchase. Are other thread sizes available?


Yes. We are able to manufacture any thread size you require. Our price list includes hundreds of the most common thread forms in industry.

We have an application with a threaded hole that is inside a counter bore or have other unique requirements. Can you help?

Absolutely. We have assisted many customers with unique requirements.


Please supply a print of the gage you’d like manufactured or call Customer Service to discuss in detail the nature of your requirement.

We do not have an established account. Can we purchase by credit card or establish an account?


Yes. JO-PLUGS® can be purchased on-line by credit card or by calling Customer Service and supplying credit card info. Establishing an account is often time consuming on the customer’s end. We do have our EIN and W-9 readily available and ETF payments can also be arranged.

How do you handle International Shipments?


We do require payment prior to shipping on International shipments. Credit card and ETF payments are the most common methods of payment.

What are your terms?

We ship 1% 10, net 30. FOB is Warren, MI unless customer UPS, FedEx or DHL account is supplied

(586)758-3800          Sales@spenceindustries.com

JO-PLUG® FAQ's