What is the best way to guarantee that a glove fits? You could measure every feature of the glove, but you will only be confident in the fit when you try it on.
The same considerations must be made when choosing between contact and non-contact thread verification methods. In the example above, contact gaging is simply putting your hand into the glove, whereas non-contact inspection involves using a camera system to measure threaded features. While New Vista offers solutions for both methods, manufacturers tend to prefer contact verification.
The majority of New Vista’s Systems are “contact”, meaning that an actual Thread Gage Member is screwed into (or onto), and then back out of the thread being verified. The system works equally well with internal or external threads.
Non-contact thread verification is used in manufacturing plants as well, but for slightly different reasons. Non-contact thread verification methods typically consist of vision systems, which use cameras, or laser-based optical scanning, to discern whether or not threads are present, and in some cases to measure the threads. The most commonly used thread vision systems are for parts and components like bolts, screws, or threaded-end rods, where the parts are passing by in rapid succession, and the objective is to pick out the ones with missing threads.
Despite their speed, Non-contact verification methods have a major disadvantage: these systems cannot guarantee assemblability. Positive assemblability means that the mating parts will assemble together correctly. With contact thread verification, if the thread gage members are selected properly, successful assembly of the gaged part (with its mating part) is assured. In addition, contact gaging can be directly correlated with hand gaging, which is familiar to everyone, and where the gages and techniques are widely accepted and very consistent across wide swathes of industries and manufacturing plants.
Prior to 2006, it was widely regarded that a contact system would not be sufficiently fast nor sufficiently reliable for use in a production environment. At that time, noncontact systems were the preferred technology, in spite of the fact that those systems could not provide a positive assemblability. The introduction of New Vista’s high-speed torque responsive devices changed peoples’ perceptions, to the extent that today a large percentage of New Vista’s orders are to replace the older noncontact installations. New Vista Contact Thread-Verification Units are extensively employed in automotive parts plants, at production facilities for aircraft componentry and for industrial and construction equipment, and for constituent parts of medical devices.
When it comes to verifying assemblability, contact verification is often the better method, although there are occasional circumstances when non-contact is suitable. Contact us today to determine the best solution for your parts!
Pipe threads are manufactured in many forms, but the most common types are straight and tapered threads. Straight pipe threads are gaged with the “GO” & “NO GO” process like regular threads, but tapered pipe threads require an entirely different gaging method: A series of L checks.
The 3 main types of L checks are the L-1, L-2 (for external threads) or L-3 (for internal threads) & the 6-Step Check. To learn about these checks in detail, visit our post detailing the Hand Gaging of NPT Threads: Hand Gaging of NPT Threads. In this video, we will be focusing on the L-1 check, as it is the most common check used in powered pipe thread verification.
There are two kinds of American pipe thread, NPT and NPTF. Both of these are tapered threads, but when screwed together tightly, the NPT, and NPTF Class 1, leaves voids at the root and crest of the threads, which, to prevent spiral leakage, need to be filled with a sealing compound at assembly. The NPTF Class 2 (Dryseal) presumably leaves no voids, and consequently requires no sealer. NPTF threads come in two classes: Class 1 & Class 2.
Thread Quality Control Series: Part 1
We hear this sentiment from manufacturing professionals all over the world. We were discussing this recently with a manufacturer in Wisconsin who machines large quantities of threaded parts. Their customer requires them to “GO” and “NO GO” verify every part. They were dealing with this requirement the way many plants do: operators stood by and spun a gage into every thread with their fingers. Unfortunately, this method was not only burdensome, but it allowed plenty of room for operator error and repetitive motion injury.
Our mission at New Vista is to work with manufacturers like you to provide the knowledge and tools you need to overcome thread quality obstacles so that you can stop spinning gages with your fingers. This series, as part of that mission, presents an introduction to thread gaging.
Attribute Gaging vs Direct Measurement:
When it comes to production inspection of threads, there are two types of inspection to consider: attribute gaging and direct measurement. Attribute gaging ensures that a feature dimensionally falls within accepted pass/fail range, by means of a gage. Direct measuring actually measures the feature, to determine where it is within the acceptable range. For most threaded parts manufacturing, attribute gaging is the more practical verification method due to its speed, simplicity, and low cost (especially in the case of internal threads).
Contact vs Non-Contact Gaging:
Gaging threads is a contact inspection procedure. While non-contact methods of inspecting threads exist, the traditional “GO” inspection method with a physical gage is preferable to guarantee assemblability (that is, to make sure that the thread will assemble properly with the mating part). Thread gages for straight threads (the common metric & unified standard) are usually supplied as a “GO” & “NO GO” gage set with a handle as shown here:
Pipe threads and other specialty threads entail unique gaging procedures that we will cover in the next feature. The most common types of thread checks for straight thread are “GO” verification for pitch diameter and verification of the minimum thread length. For the vast majority of manufacturers, employing these two verifications at 100% is sufficient. When “NO GO” gaging is employed it is typically only sampled, not checked 100% of the time.
“GO” gaging, by its nature, is a composite check; it verifies for several attributes all at once, and, through that composite verification, it guarantees assemblability. So, a “GO” gage for an internal thread would guarantee that the thread’s pitch diameter, the minor diameter and the major diameter are all sufficiently large. If the gage is employed advantageously, it will also guarantee that the thread is of sufficient length (depth).
“NO GO” Checks:
“NO GO” gaging, except in rare instances, can only ever check for one attribute at a time. Manufacturers may be required to “NO GO” verify a thread’s pitch diameter or minor diameter. In either case, the “NO GO” gage ensures that the pitch or minor diameter is not oversized which would cause the mating part to be loose. Standards differ depending on part material, thread size and thread length, but the general rule of thumb is that the “NO GO” pitch diameter gage should not go more than 2-3 turns into the thread. Be sure to review your thread’s particular specifications. A “NO GO” minor diameter gage is as simple as using a gage pin or gage ball to ensure that it does not enter the thread.
In situations where both “GO” and “NO GO” verification is required, New Vista has developed combination gages that will perform both checks in one pass on thru threads, saving time and costs.
The “GO” and the “NO GO” checks are a critical aspect of any manufacturing process involving threads, but you don’t have to do them with your fingers. If you would like to find out how you can expedite your thread inspection process, or if you have additional questions about thread gaging, contact one of New Vista’s Applications Engineers today. Expert applications service is available from our U.S. location and in several other countries as well.
Today our RT and CRD Thread-Verification Kits are available for sale on NewVistaCorp.com! Off-the-shelf Kits start at $899 and ship out in 2-3 days. You can read on below to learn more about the Kits or watch our video here:
Each Kit gives you everything you need to start verifying your threads with your own thread gages. The Kit includes:
- A CRD or RT Handheld Thread Unit
- New Vista’s patented Torque Limiting Device
- A Quick-Change Toolholder
- Tool Adapters for the three most common taper shank gage sizes
- Battery and charging station
Additional Tool Adapters for reversible and straight shank gages are available for sale on our website. Visit our shop or contact one of our Applications Engineers to discover how to improve your thread checking process today!
You asked. We listened.
For the last 25 years while we have worked with manufacturers to provide fast and reliable thread-verification solutions we got one question a lot: “Don’t you have something you can send me quickly? I need to check these threads today!”
Well, now we do. We’re proud to announce our new line of Handheld Thread-Verification Kits that ship out in 2-3 days. The Kits will be available for order directly from our website. Look for our email later this month with more details about the kits and the opening of our web store! In the meantime, watch this video to see these new Handhelds in action:
The PPT Thread Machine is New Vista’s latest and most affordable bench-mounted, manually-operated system to date. It can be used for thread gaging or thread remediation (chasing or retapping). Its small footprint (400mm long, 280mm wide, 267mm high) makes it portable and it requires no programming. These factors allow for shorter deliveries and easy set-up: just plug it in, and it is ready to use. To verify a part, the operator simply pushes the part forward; to reverse, the operator only needs to pull back. If needed, this system can be operated with the kinds of hand gages that you already have, and without any fixturing or part guides at all, but for fast cycles guides can be of considerable benefit.
The PPT is supplied in two configurations: the basic PPT Unit (no depth control), and the PPT with depth control. Adding the depth control feature allows the PPT to run faster cycles, eliminate the possibility of crossthreading, and display a full-area green flash to indicate a good part. In either configuration, the PPT is faster and more ergonomic than any handheld unit, which necessarily requires the operator to align small or awkwardly-shaped parts by hand. This system is designed to reduce both awkwardness and cycle time, while simultaneously eliminating operator fatigue.
The New Vista PPT is suited for a wide range of applications and offers speed and flexibility in an affordable package. Discover how the PPT can be used for your quality application needs by contacting us today.
We strive to offer you the very best solutions for your thread inspection process, and our Robotic Thread System is no exception.
Tired of checking all your threads by hand? Out of all New Vista’s automated thread-verification solutions the RTU is the most versatile and effective when multiple thread sizes are involved. Learn more about the RTU Thread-Verification Solution at our website or contact us today to discuss your application.
Given parts with threads all over the place and at different angles (such as a Crankcase, above): what is the best way to verify all of the threads? Fixed automation systems tend to be inflexible and expensive, and hand gaging is inefficient and unreliable, with a high probability of human error leading to missed threads. The best solution? Often it’s the New Vista Robotic RTU.
The RTU is the successor to New Vista’s popular and acclaimed STH-R1 Robotic Unit, which has been employed in production applications around the world since 2012. Now, New Vista’s new RTU Robotic Systems offer the flexibility and agility required to meet any challenge, at a fraction of the cost of fixed automation.
The RTU will easily integrate with robots of any make or model. The thread gage members employed for each application can be changed automatically, employing New Vista’s Tool Docking System. Torque and depth settings are changed automatically during operation to accommodate any thread size. New Vista’s Compliant Toolholders (supplied with every System) will accommodate both rectilinear and angular misalignments. And a new breakaway feature ensures that tooling and parts are not damaged in the event of an accidental crash.
The New Vista RTU is suited for a wide range of applications and offers speed and flexibility in an affordable package. Discover how the RTU can be used for your quality application needs by contacting us today.
Versatility can be hard to come by in the world of volume manufacturing inspection equipment. Dedicated machines can be pricey or unable to adapt to new applications. Units suitable for spot checks lack adaptability for more rigorous applications. In today’s environment of newly emerging challenges, an affordable Unit flexible enough to adapt to multimodal use will save you time, money, and the headaches of dealing with quality issues.
The New Vista HTU Unit has been specially designed as a solution to these challenges. Compact and lightweight, this electric-driven system can be used three different ways:
- As a handheld Unit, the HTU is ideal for spot checks and sampling, or low volume verification of parts in a variety of sizes. Tethered to a control, the HTU offers preset depth sensing, automatic reversal out of threads, settable torque, and a green pass light, giving the operator a powerful set of features that can be quickly adapted to new parts as the need arises.
- To run high volumes of small parts (like nuts or sleeves), the HTU can be bench-mounted. This adaptation allows the operator to present parts to a fixed spindle by hand for thread verification that is both quicker and more ergonomic than holding small parts while running the HTU into or onto them. The bench-mounting option reduces operator strain while also reducing cycle time, mimicking the functionality of bench-mounted stations at a fraction of the cost.
- For large or unwieldy parts with multiple threads of different sizes, the HTU can be mounted to a counterbalanced pantograph in the HTU/SVX configuration. The HTU/SVX keeps the HTU Unit square to the thread it is checking while reducing both operator effort and error. Used in conjunction with New Vista’s Quick-Change Tool Docking equipment, changeover between thread sizes is nearly effortless. Odd-angled threads that would otherwise require repositioning the part can be verified by quickly uncoupling the HTU from the pantograph. See the HTU/SVX in action verifying threads in a Crankcase.
The New Vista HTU is suited for a wide range of applications and offers the operator speed and flexibility in an affordable package. Discover how the HTU can be used for your quality application needs by contacting us today.