Precision Gages

British thread gauges are an essential tool used in many industries to measure the dimensions of screw threads. They come in a range of sizes and types, each designed to measure specific threads. In this article, we will explore the different types of British thread gauges and their uses. Whitworth Gauges Whitworth gauges are used to measure threads with a 55-degree angle, also known as Whitworth threads. These threads were commonly used in British engineering until the 1950s. Whitworth gauges come in a range of sizes, from 1/16 inch to 6 inches. British Standard Pipe (BSP) Gauges BSP gauges are used to measure threads on pipes and fittings. They come in two types: parallel and tapered. Parallel BSP threads have a constant diameter, while tapered BSP threads have a gradually decreasing diameter. BSP gauges come in a range of sizes, from 1/16 inch to 6 inches. British Association (BA) Gauges BA gauges are used to measure small threads commonly used in precision engineering. These threads have a 47.5-degree angle and come in sizes ranging from 0BA to 22BA. BA gauges are commonly used in the manufacture of clocks, watches, and other precision instruments. British Standard Fine (BSF) Gauges BSF gauges are used to measure fine threads with a 55-degree angle. They were commonly used in British engineering until the 1950s. BSF gauges come in a range of sizes, from 1/4 inch to 1 inch. British Standard Whitworth Fine (BSWF) Gauges BSWF gauges are used to measure fine threads with a 55-degree angle. They were commonly used in British engineering until the 1950s. BSWF gauges come in a range of sizes, from 1/4 inch to 1 inch. In conclusion, British thread gauges come in a range of types and sizes, each designed to measure specific threads. The type of gauge used will depend on the type of thread being measured and the industry in which it is being used. It is important to use the correct gauge for each application to ensure accurate measurements and reliable results. Additionally, it is important to keep thread gauges clean and properly maintained to ensure their accuracy over time. With the proper use and care, British thread gauges can provide accurate and reliable measurements for years to come.  Written by WESTport Corporation. All rights reserved. Any reproduction is strictly prohibited.

Introduction ANPT plug gages are used for gaging internal ANPT threads. The process involves screwing up the plug gage by hand into the internal thread of the pipe or product at hand. In comparison to other gages of the ANPT thread family, the ANPT L3 plug gage is used to check the threads that will be engaged once the product is tightened with a wrench for practical application. Besides the ANPT L3 plug gage, there are: ANPT L1 thread plug gage which is used to check the engagement of the thread elements when the product will be tightened by hand, and ANPT 6-step plain plug that is used for checking the minor diameter of the female fitting. More On ANPT L3 Plug Gage The process for gaging the internal thread of a product involves not just ANPT L3 plug gage, but all three gages mentioned above. First off, the thread is gaged with ANPT L3 plug gage, also called the limit-type L1 taper thread plug gage. The gaging notch that most nearly represents the size of the thread is noted. Although the ANPT threads are similar to NPT threads, the difference in the application for aeronautical purposes dictates that they must be controlled very carefully for taper, thread form, and diameter. This is because up until the length of 2-inch size, the ANPT and NPT threads are almost identical and have a requirement of an L1 gage. From the primary L1 threads that are measured with the L1 gage, the threads thereafter are referred to as the “L3 length” which is measured by the ANPT L3 plug gage. These are the threads that will be engaged when the threads of the product are tightened with a wrench. ANPT L3 plug gage is also a limit type gage whose total length equals L1 + L3. But despite this, the gage only has four threads at the small end. This is why, for a thread to be accepted on the L3 gage, the position of the gaging notch must coincide with half turn of the position previously noted on the L1 gage. The ANPT threads have a distinctive design to make a true seal that eliminates the need for a sealant. They make a true seal by crushing in on themselves. The ANPT L1 and ANPT L3 threads are needed for measurements of the female threads. Together, L1 and ANPT L3 plug gages measure the:  Lead Taper Pitch diameter, and Major diameter For measuring the minor diameter of the internal thread, the amount of the truncation is noted. Since the pitch diameter and truncation vary with limits, the minor diameter will also. The three-pitch diameter gaging positions are: Basic Minimum Maximum These pitch diameters necessitate 3 pairs of maximum and minimum truncation steps that amount to a total of 6 positions. Conclusion: At WESTport, we provide you with quality that you can trust. We are manufacturers who are ISO 9001 and ISO/IEC 17025 accredited which means each of our products complies with the strictest industrial standards. Ranging from the plain and threaded plug and ring gages to any custom needed gage to your blueprint specifications, WESTport is your one-stop-shop for all your quality assurance needs. We are committed to providing premium quality products in a timely manner with our industry guarantee to beat any competitor's price. Written by WESTport Corporation. All rights reserved. Any reproduction is strictly prohibited.

Introduction: ANPT L-1 Plug Gage is used to check the internal thread rings of the aeronautical equipment such as pipes, fittings, plugs, etc. ANPT or Aeronautical National Form Pipe Taper Thread Plug Gages are used in applications where gasket, straight threads, or O-rings are not applicable; particularly in aeronautical applications. More About ANPT L-1 Plug Gage: ANPT L-1 Plug Gage is used to first gauge the internal threads. The gaging notch that most accurately represents the size of the thread is hence taken a note of. It is used to check the major diameter, pitch diameter, lead, and taper. The major diameter is only measured to the upper threads which are hand-tied. The later threads, which are measured by ANPT L-3 Plug Gage are measured for wrench tight position. The parts checked with ANPT L-1 Plug Gage are considered acceptable when they come flush with the notch. This means they will come close to either plus one or minus one turn and check the first four screw threads. Similar to NPTF, ANPT threads also employ an L1 and an L3 gage to measure the first four and the last three thread rings. Likewise, they both require plain taper 6-Step Crest-Check pipe plug gauges. The L-1 gage, more particularly, the ANPT L-1 Plug Gage is first used to gauge the size of the hole in contrast to the screw thread tolerance which could be either basic, minimum, or maximum. Albeit the ANPT internal pipe threads are practically the same as the pipe threads of NPT, they have a distinct application for their use in aeronautical applications which is why their diameter, taper, and thread form are very carefully controlled to form a seal that doesn’t need application of external sealants. These sealed threaded joints are also needed in applications where O-rings, gaskets, or straight threads won’t get the job done. Similar to ANPT L1 plug gage which checks the external diameter, the ANPT ring gages are used for checking the external diameter of pipes and ends with rings. The plug has a distinct difference from the basic NPT plug where in addition to its basic steps, we have the maximum and minimum steps that are used for measurement as follows: The product is in tolerance if its face is between the maximum and minimum steps of the plug. To check the depth beyond L1 depth which is measured with ANPT L1 plug gage, the ANPT L3 plug gage is used. Furthermore, the truncation is checked with a six-step plain taper plug gage which includes maximum and minimum truncation steps for each of the three-pitch diameter conditions which are maximum, minimum, and basic. It is also noteworthy that there should be no shake or wobble during the measurement. This is an indicator of taper error and must be tended to on an immediate basis. Conclusion: At WESTport Corporation, we have been providing the industry worldwide with precision measuring instruments and calibration services since 1989. WESTport employs state-of-the-art measures to ensure all our products comply with the ISO 9001, and ISO/IEC 17025 standards. Moreover, our expanded product line includes thread and plain gages, API Plug and Ring Gages, taps and dies, medical gages, spline gages, and full-service metrology laboratories for tool calibration, repair, and onsite services. Written by WESTport Corporation. All rights reserved. Any reproduction is strictly prohibited.

Introduction Taper pipe NPTF 6 step plug gage is used in conjunction with L1 plug to inspect the profile of the internal threads or crest truncation. In other words, its purpose is to measure the pitch diameter size of the essential components of the dry seal. It ensures conformance to dry seal requirements because to get an accurate measurement, it is vital to determine the distance from the L1 gage to the part. More About Taper Pipe NPTF 6 Step Plug Gage The 6-steps plug gage is used for testing the root or crest of the product thread in question. Since the three zones of the gage are overlapping, we need six steps for measurement. These six steps are as follows: MX MXT B BT MN MNT How Does It Work? If the result of the L1 gage indicates that a part falls in the minimum range, then it must fall between B and BT on the Taper pipe NPTF 6 step plug gage. If the part lies in the basic range, then it must fall between B and BT on the Taper pipe NPTF 6 step plug gage. Finally, if a part lies in the maximum range, it must fall between MX and MXT on the Taper pipe NPTF 6 step plug gage. Taper pipe NPTF 6 step plug gage is required by the NPTF class 2 threads. It is also known by another name which is Crest-and-Root Truncation Gage. Taper pipe NPTF 6 step plug gage is not threaded, rather, it has six steps grounded into it. The tool is used by inserting it into the hole and then reading the pairs which tell us the high and low limits of the three aforementioned conditions. This extra check is required by the class 2 threads. These gages are designed to the specifications of the Bureau of Standards Handbook H-28 and ANSI Standards B1.20.3 and comply with MIL-P-7105 Military Standards. Conclusion Taper pipe NPTF 6 step plug gage is essential for the measurement of the Crest-and-Root Truncation. Having no threads of its own, it has 6 steps that help in the identification of the thread in either minimum, basic, or maximum condition. They help us in gaging the internal diameter of holes that have been drilled into parts or machines. They are an essential tool for every quality control agent, engineer, machinist, or inspector to get an idea of the characteristics of the part in question. These measuring methodologies are essential and prevent the employment of difficult methodologies for measurement that may be more time consuming or simply not implementable for everyone. Based on that, a part is either accepted or rejected. At WESTport we offer a wide range of the highest quality precision tools, taps and dies, gages, and full-service ISO 17025 metrology laboratories for tool calibration, repair and onsite services. We are continuously improving our services and products to maintain our position as a global leader in our industry. Written by WESTport Corporation. All rights reserved. Any reproduction is strictly prohibited.

Introduction Taper Pipe NPTF L3 Plug Gage is used for the inspection of the L-3 length of the engagement for taper and wrench tight. What makes NPTF gages different from NPT gages is that they are considered dry seal pipe threads. They are also called relationship gages which are used for inspecting the taper coupling and wrench engagement of the internal threads or couplings. Taper Pipe NPTF L3 Plug Gage is used in conjunction with NPTF L1 gages hence the name “relationship gage”. Use When internal threads are gaged, Taper Pipe NPTF L3 Plug Gage is one of the three main members used where the Taper Pipe NPTF L3 Plug Gage is used to checking the threads that will be engaged at the stage of wrench tightening. Since the gages are different in terms of dimension, it is vital that they must not be interchanged from one another. NPTF vs. NPT The primary difference is in the name, then there is a major difference of no sticking medium used like Teflon tape or pipe dope between the two threads in NPTF. NPTF gages are designed to bear a high critical crest tolerance which is why they are commonly inspected with a smooth 6 step plug or ring gage. The gage is used in conjunction with the NPT L1 gage that helps in establishing the tolerance of the product in question (whether the tolerance is min, nominal, or max.) The L3 in the name of Taper Pipe NPTF L3 Plug Gage refers to the need for a secondary inspection which may be required on the said threads for which the L3 plug is used. Do note that the plug is used for the inspection of the internal threads whereas ring gages are used for the inspection of external threads. Both L1 and L3 plugs are used on threads that are not plated. As such, it is imperative that the gage must not move 0.5 turns (+/-) from the position of the L1 gage. Gages that are plated have a different tolerance. Precautions It is vital that the Taper Pipe NPTF L3 Plug Gage must be treated with diligence as a precision tool as any type of mishandling or misuse, or forced use can cause unwanted deformities or nicks. This can compromise the integrity of the gage hence the measurements. Also, the gage must never be forced into a part that is under check. Moreover, keep the gage separate and never cram it with other tools as it may damage the threads of the gage. When you are done with the use of the tool, it is advised that you should oil or grease the tool to protect it from rust. Finally, if Taper Pipe NPTF L3 Plug Gage is to be shipped over long distances, store it in a separate container with insulation to prevent it from being damaged. Conclusion Taper Pipe NPTF L3 Plug Gage is a part of class 2 gages that are used specifically for measuring the crest and threads. The plugs themselves can only be checked with a master thread plug which is why it is advised to keep a spare. Production units with regular and excessive use of Taper Pipe NPTF L3 Plug Gage are advised to have several spares at hand along with a master thread plug to regularly check on wear and tear of their Taper Pipe NPTF L3 Plug Gage. Written by WESTport Corporation. All rights reserved. Any reproduction is strictly prohibited.

Introduction The Taper pipe NPTF L1 plug Gage, also called relationship gage are considered dry-seal pipe threads. Essentially, Taper pipe NPTF L1 plug Gage is used for the inspection of the pitch diameter of the hand tightened L1 length of any engagement. The NPTF part stands for “National Pipe Taper Fuel” where their requirements are spelled out in ANSI B1.20.3. NPTF vs. NPT Comparatively speaking, both, the Taper pipe NPTF L1 plug Gage and the NPT version will have identical taper-per-inch, threads-per-inch, and pitch diameter. What is different is their crest and roots of threads as well as their major and minor diameters. Though NPTF threads crest is well within the required parameters of NPT, they still have a smaller range in comparison. Where NPT threads are considered general-purpose pipe threads, NPTFs are reserved for more critical applications. In a sense, both are designed to screw together and that much is simple enough, but where NPT requires a “seal” to be truly leak-proof, NPTF doesn’t. Both NPT and NPTF standards are strikingly different in terms of threads as even the L1 gage requirements both have a difference of ½ in. size-wise. They are not interchangeable which is where the Taper pipe NPTF L1 plug Gage comes into play. The NPTF threads require more assembly for size check which is not possible with the NPF plug gage. Only a Taper pipe NPTF L1 plug Gage can check NPTF threads. More About Taper Pipe NPTF L1 Plug Gage Taper pipe NPTF L1 plug Gages are specifically designed for inspecting the functional thread and pitch diameter for the components with internal threads. The L1 indicates that Taper pipe NPTF L1 plug Gage belongs to class 1 thread gages for a functional check of taper deviations and continuation of thread beyond the L1 length of engagement. Being an L1 plug, the Taper pipe NPTF L1 plug Gage inspects the hand tight engagement of an internal thread or couplings as well as the functional size. At WESTport, all Taper pipe NPTF L1 plug Gages are manufactured as per ANSI/ASME B1.20.5 and come along with a Free NIST certificate of accuracy. They are designed with hardened steel or similar materials which prevent the degradation of the threads. Moreover, these gages are designed with recessed minor thread diameter for safe functionality. The ergonomic handle provides a maximum comfortable grip. Due to the reduced thread start diameter design, it ensures easy insertion of the gage. Conclusion The Taper pipe NPTF L1 plug Gages have tolerance of one turn (+/-) from either the small end face of the ring or notch on the plug and it falls between one of the following sets of notches: MN & MNt B & Bt MX & MXt The notches are in relation to from where L1 gets measured. At WESTport, you can expect to buy top quality Taper pipe NPTF L1 plug Gages with quality you can trust. With an extended line of products pertaining to Quality Assurance Products and Services, we are at the forefront of serving the industry as leaders in precision tools and related services. Written by WESTport Corporation. All rights reserved. Any reproduction is strictly prohibited. The Taper pipe NPTF L1 plug Gage, also called relationship gage are considered dry-seal pipe threads. Essentially, Taper pipe NPTF L1 plug Gage is used for the inspection of the pitch diameter of the hand tightened L1 length of any engagement. The NPTF part stands for “National Pipe Taper Fuel” where their requirements are spelled out in ANSI B1.20.3.

Introduction: Taper pipe NPT L1 Plug Gage is a piece of versatile measuring equipment that is used to check the integrity of the internal threads to ensure they meet the required standard precisely. As a type of measuring tool, they need to be sourced from reliable manufacturers to ensure the accuracy of measurement every single time. Also called Go No-Go Plug Gages (more on this later), the engagement with the internally threaded part must be done with delicate force. A Reliable Tool For Test: As a hand-operated tool, you need to ensure a smooth engagement or you risk damaging the threads. Standard industry practice is to give the Taper pipe NPT L1 Plug Gage three revolutions while inspecting the threads of an object. For instance, if you are measuring the threads of a nut, use the Taper pipe NPT L1 Plug Gage and give it three complete rotations. If the threads are clean, you will find that it goes all the way. If it becomes jammed or stops, stop turning immediately as the threads of the nut have obstructions and hence failed the test. Uses: Taper pipe NPT L1 Plug Gage is used by quality inspectors, manufacturing engineers, technicians, and machinists for the inspection of thread components and their precise calibration. They are an essential part of any quality control process to ensure the threaded components are made with the required calibration and are free of any obstruction. Types: Taper pipe NPT L1 Plug Gage are available in several types including: Go Plug Gages – A hand-held single-ended gage that has a handle and pin, which is very precisely machined for accurate verification of the dimensional tolerance of a threaded hole. Go Plug Gages are offered with No-Go Plug gages as they are both used in combination to determine whether a hole falls under the acceptable limits or not. It helps in the testing of the “minimum dimensional limit” of a threaded hole which is the representation of the “maximum amount of remaining material on the part under inspection”. If a Go Plug Gage fits into a hole, it is acceptable, if not, then the piece must be discarded. No Go-Plug Gage – It is used for the validation of the maximum dimensional limit of a threaded hole. This directly corresponds to the “minimum acceptable amount of remaining material” that should be on the part under inspection. If the No-Go Plug Gage doesn’t fit into the hole, it means that the hole diameter is “below” the acceptable limit. If it does fit, it means that the hole diameter is above the acceptable limit. The only acceptable condition is if Go Plug Gage fits and No-Go Plug Gage doesn’t fit. Go No-Go Plug Gage – This is a combination of both Go Plug Gages with one on each side. It speeds up the inspection process and simplifies its use. The sides are either labelled or color-coded for their identification but the visual difference is also quite obvious. Advantages: A Taper pipe NPT L1 Plug Gage is simple and easy to use A WESTport Taper pipe NPT L1 Plug Gage is marked with pitch diameter for easy identification WESTport Taper pipe NPT L1 Plug Gage are available in a variety of metric sizes A WESTport Taper pipe NPT L1 Plug Gage is highly accurate WESTport Taper pipe NPT L1 Plug Gage ensures fast testing and ensures easy hand operation Conclusion WESTport Taper pipe NPT L1 Plug Gage is available in a variety of styles and over a wide range of measurements. WESTport stands proud as a manufacturer of quality assurance products with a commitment to client satisfaction and the provision of reliable products as an industry leader. Written by WESTport Corporation. All rights reserved. Any reproduction is strictly prohibited. WESTport Taper pipe NPT L1 Plug Gage is available in a variety of styles and over a wide range of measurements. WESTport stands proud as a manufacturer of quality assurance products with a commitment to client satisfaction and the provision of reliable products as an industry leader.

Threaded fasteners play a vital role in the construction of a wide range of products. Without accurate thread sizing, a fastener's ability to provide a secure connection is compromised. Manufacturers rely on thread gages to check fastener specifications and ensure the integrity of all threaded fasteners leaving their facility. Your thread gages are designed to be durable, but they may sustain some damage over time. If you know how thread gages can sustain damage, you will be equipped to identify faulty thread gages before they create serious problems in the future. 1. Abrasions One of the most common ways that a thread gage can sustain damage is through contact with the fasteners it is measuring. A fastener is either threaded through or into the thread gage. The threading process can create friction that causes abrasions to form on the interior surface of the thread gage. Abrasions have the potential to alter the profile of the thread gage, making it impossible to produce an accurate reading when using the damaged thread gage to take measurements. Be sure that you inspect your thread gages often for evidence of abrasions and replace damaged gages quickly to preserve the integrity of your fasteners. 2. Expansion Many of the thread gages used in modern manufacturing facilities are made from steel. Steel is a metal alloy that offers great strength and durability, but it does have a tendency to expand over time. The molecules within a steel product can start to relax once the steel is put into use. Environmental factors like temperature and humidity can influence the rate at which steel expands. You want to ensure that you are using your thread gages in a controlled environment. Fasteners should only be tested in temperature-controlled settings, and thread gages must be stored in a temperature-controlled space to prevent any damage caused by expansion. 3. Burrs The dimensions of a thread gage must be exact if you want to ensure that your fasteners meet strict design specifications. Anytime one metal product comes into contact with another, it's possible for burrs to form. Burrs are the result of contaminants that have cut their way into the surface of your thread gages. A burr can make it impossible to obtain an accurate measurement using your thread gage, and this could result in a decline in fastener quality. Inspect all thread gages used in your facility often to ensure burrs don't cause threaded fastener problems in the future. To learn more about thread gages or to replace your worn-out ones, contact a supplier.