Common Tools For Riveting And Welding Inspection

Common tools for riveting and welding inspection

When performing zinc-nickel alloy electroplating anti-corrosion work on riveted weldments , the most worrying thing is rework. Once there are problems with the welds or conditions at the riveting points, no matter how excellent the subsequent anti-corrosion work is, it will be in vain. Therefore, the key to inspecting this link is to select the correct tools for riveting and welding parts, electroplating zinc-nickel alloy anti-corrosion , and firmly grasping the accuracy and pertinence. The three types of tools mentioned below are the most indispensable and important tools for workshop quality inspectors every day.

Dimensional measuring calipers and micrometers are basic skills

Let’s talk about calipers first. There is a steel structure factory located in Changzhou, Jiangsu. There is a quality inspector named Master Wang who does this job. He has to use electronic calipers to randomly inspect at least 30 rivet head diameters every day. This kind of caliper has the ability to accurately read to two decimal places, that is, it has an accuracy of 0.02 mm. If its accuracy is used to measure the width of the weld groove, it is completely up to standard. If during observation it is found that the width of the welding joint is 0.5 mm narrower than the width required by the drawing, then the welder must be notified immediately to perform repair welding. Otherwise, when electroplating zinc-nickel alloy, the liquid will easily accumulate in the narrow gap, causing sagging.

As for the micrometer, its accuracy is ten times higher than that of the caliper and can reach 0.001 mm. In September 2025, a pressure vessel factory in Linyi, Shandong Province used ordinary calipers to measure the bolt hole diameter, resulting in the shaft diameter fit being too loose after riveting, and the entire batch of products fell off during the vibration test. Later, a mechanical micrometer was used to measure the critical apertures one by one, and the error was controlled within 0.01 mm, which solved the problem. For occasions where riveted weldments need to be electroplated, the aperture accuracy directly affects the uniformity of coating coverage.

A special gauge for welding seams measures three items in one foot

There is a pocket tool designed specifically for welders called a weld gauge. On the container production line in Ningbo, Zhejiang, there is an on-site inspector, Mr. Zhao, who carries a stainless steel weld gauge with him. This weld gauge is less than 15cm long. With it, Mr. Zhao can measure the reinforcement, offset and leg size of a 1-meter-long weld in two minutes. It is stipulated here that the reinforcement cannot exceed 3 mm. If it exceeds the common tools for riveting welding inspection, the top coating will be thin during electroplating; the offset amount must be less than 10% of the plate thickness, otherwise the zinc-nickel alloy solution will accumulate at the step and form yellow spots.

First, there is another benefit to this gauge, which is that it is easier to carry. For example, when you are at the construction site of a large outdoor storage tank, there is no stable power supply or table, and it is impractical to transport electronic equipment at this time. However, with a welding gauge that costs only a few dozen yuan, you can quickly complete the spot inspection work. In January 2026, there was a petrochemical project in Qinzhou, Guangxi. It was based on this weld gauge that three welds with wrong edges exceeding the standard were discovered. Through timely repairs, the risk of leakage in the later period was avoided.

Magnetic particle inspection specializes in detecting hairline cracks on the surface

The magnetic particle flaw detector is the nemesis of surface cracks in ferromagnetic materials. In a bridge steel structure factory in Hefei, Anhui , riveted weldments are electroplated with zinc-nickel alloy for corrosion protection . Workers will first spray the reddish-brown magnetic suspension towards the weld, and then carry out electromagnetic flux. If there is a weld with a width of 0. If there is a hairline crack of 1 mm, the magnetic lines of force will leak there, attracting the magnetic powder and forming a clearly visible black line. It should be noted that this operation must be carried out after the temperature of the welding seam is reduced to normal temperature, because the magnetic powder will fail in the hot state.

From an actual case of a river crossing project in Wuhan in November 2025, quality inspectors used magnetic particle inspection to spot-check the 200-meter-long roof welds and found 7 tiny cracks that were invisible to the naked eye. If it is sent directly to zinc -nickel alloy for electroplating without treatment, these cracks will be covered by the coating. However, after half a year of use, the stress will cause the cracks to expand. Therefore, this process cannot be omitted.

Ultrasound and rays are used to perform internal CT on welds

That ultrasonic flaw detector that can see through the inside of 200 mm thick metal. At a liquefied natural gas storage tank construction site in Shenzhen, Guangdong, the inspector squeezed the coupling agent, which is a particularly viscous industrial gel, onto the front end of the probe, and then slowly slid it against the weld. A waveform will pop up on the instrument screen. If there are defects such as air holes or lack of fusion, the waveform will suddenly jump high. This detection method is particularly suitable for detecting girth welds of pressure vessels, because once leakage occurs, it will be a serious accident.

Radiographic inspection is used as a last resort. In February 2026, there was a nuclear power equipment factory in Shanghai that used industrial gamma ray sources to detect butt welds of main pipelines. The rays pass through the component and are imaged on the film. This imaging can detect tiny slag inclusions of 0.1 mm level. Although the cost of taking a film exceeds 500 yuan and requires isolation, the film can be permanently stored as a quality certificate. For riveted weldments that have to withstand high pressure and corrosive environments, the money is well spent.

Hardness testers and torque wrenches maintain performance bottom line

A Leeb hardness tester that can be tested directly on site by tapping. In August 2025, a wind power tower factory in Tianjin discovered that the hardness value of the welding heat-affected zone suddenly changed, suddenly soaring from 220 to 320. Afterwards, a Leeb hardness tester was used to conduct a review on site, and it was confirmed that the material had become embrittled. The reason is that the welder cools down too quickly. If the electroplating operation is carried out without dealing with this problem, the adhesion of the zinc-nickel alloy layer on the brittle and hard surface will decrease, and the skin will peel off soon.

A tool with the function of checking the tightening force of high-strength bolts is a torque wrench. When installing a steel structure roof on a sports stadium in Chengdu, Sichuan, workers used a digital display torque wrench to preset a torque value of 480 Nm. When the wrench reaches this value, it will make a beeping alarm sound. First, it can ensure that the tightening force of each riveting point is in a uniform and stable state, and there will be no situation where some parts are too loose and some parts are too tight. If the torque deviation exceeds 10%, then the liquid left in the thread gap after electroplating will be difficult to clean, which will accelerate the corrosion rate.

After reading these three types of tools, what you are thinking about is which type of tool inspection is most likely to be neglected by everyone before the rivet welding parts in the factory are electroplated with zinc-nickel alloy. Welcome to leave a sentence in the comment area to let us know. Don’t forget to like and forward this behavior to more colleagues who are doing quality inspection work😃.