by Emily Newton
Many people do not notice the ridges and valleys — known as threads — bordering the connection points of pipes. However, for professionals such as plumbers and gas industry workers, improving their pipe-threading techniques is essential to getting better results in their work.
Adding the necessary threads to pipes enables the use of specialized fittings that connect the pipes and prevent leaks. Understanding several best practices will lead to excellent outcomes.
1. Become Familiar With Project Specifics
People must start by understanding what their particular projects require. For example, depending on the hose and tube fittings, there are different pipe-threading techniques to select. Some of the most common thread types are:
- The American National Taper Pipe (NTP) and National Taper Pipe Fuel (NPTF) threads
- The British Standard Pipe female thread, British Standard Parallel or British Standard Tapered
- The Society of Automotive Engineers (SAE) Unified Coarse, Unified Fine or Unified Extra Fine
- Metric Parallel or Metric Tapered
The SAE thread types are frequently selected for oil and gas fittings, often seen alongside the British and American thread options.
Besides understanding the thread type associated with an upcoming project, pipe professionals must know that pipe diameters need varying numbers of threads. A pipe with a three-quarter-inch diameter typically has eight or nine usable threads.
2. Know How to Identify the Thread Type
A pitch gauge and caliper are the two main tools needed to verify the existing thread type. This step can help the user make more appropriate decisions during the later stages of the pipe-threading process.
The pitch gauge measures the distance between thread crests. However, pipe threaders must know whether their thread type expresses the measurement in inches or millimeters. For example, Metric Parallel and Metric Tapered use millimeters, but the American National Taper Pipe and National Taper Pipe Fuel threads rely on inches to determine measurements.
People use calipers to measure thread diameter. They must first check whether the threads are external (male) or internal (female). In the former case, the caliper measures the pipe’s outside diameter but takes measurements inside for internal threads. Choosing a digital instead of a manual caliper can save time and increase accuracy.
3. Choose the Appropriate Pipe-Threading Machine
Many pipe-threading machines must plug into wall outlets. Unfortunately, that reduces a user’s productivity by requiring them to work close enough to the nearest outlet. Fortunately, some manufacturers have addressed this limitation by creating more convenient options.
For example, one company introduced an industry first in 2023 with its cordless pipe-threading machine. In addition to cord-free operation, this equipment works with a collapsible transportation cart that features gas-assisted springs to bring the machine up to the desired working height.
Mechanical threaders usually work with manually operated ratchets, requiring people to physically insert the die heads and cut threads into the pipe. These options work best for small, lightweight pipes and minor projects due to the labor-intensive operation. Alternatively, there are electric threaders that automatically rotate the die heads. People commonly use these for larger, industrial-scale projects since they get faster results than manual models.
Handheld threaders are the nearest counterparts to cordless versions. These are lightweight and easy for operators to carry to different places while working. They feature electric-powered die head rotators for efficiency.
4. Perform Quality Control Checks
No matter which pipe threading techniques someone chooses, they should always carry out quality control checks to ensure safe, high-performance results. Visual inspections can reveal various issues that could compromise a pipe’s safety and effectiveness. For example, friction and adhesion between sliding surfaces cause galling, which appears as raised lumps on a thread’s surface. Galled threads can occur quickly and spread, especially when the pipe lacks proper lubrication.
However, light scratches on a thread will not affect the connection’s integrity. Knowing how to identify visual issues and whether they are problematic allows a pipe threader to feel confident in their work.
Beyond checking threads visually, people should use thread gauges to check that the achieved outcomes are within a product’s specifications. They can do this by using go and no-go gauges.
A go gauge measures the mating size of external threads and can determine if unthreaded flanks are long enough. They screw onto the items under measurement. Screwing the go gauge up the full length of the thread by hand and without significant force means the threads meet the intended parameters.
Conversely, a no-go gauge does not screw up the whole length of threaded items. It measures the threads’ pitch diameters and should not turn more than a few rotations. This quality control device verifies that the pitch diameter of the threads is not less than a set minimum.
When using go and no-go gauges, people must manually turn the part while attaching the gauge. Since this process can take five seconds to several minutes per part, some people have investigated automation. One option is letting a robotic arm load parts into a motorized thread gauge that provides mechanical thread verification.
5. Learn About New Pipe Materials
People should also be informed about emerging technologies resulting in new pipe materials. Many ongoing efforts relate to sustainability and how industry professionals could make specific choices to reduce emissions and overall environmental impacts. For example, bamboo can be harvested in as few as three years, but timber grows over decades. Timber’s much longer growth period makes it harder to replenish used resources, which is why bamboo has become popular in construction.
Similarly, as pipe materials change, so may the pipe-threading techniques people choose. In one recent example, a company made an existing pipe option more sustainable by creating plastic with industrial waste, such as vegetable fats.
These lead-free options are ideal for drinking-water projects due to their smooth inner walls and cavity-free jointing technology that prevents contamination. The pipes also have a self-sealing design that eliminates using O-rings. Statistics indicate the production process results in 90% fewer CO2 emissions than the company’s older, less sustainable design.
Take Pipe-Threading Techniques Seriously
A pipe’s threads are the critical but sometimes overlooked features that ensure safe functionality. Following these tips encourages pipe-threading professionals to pursue continuous improvement and career advancement that can keep them employed and in demand.
