On-site machining is a specialized field that involves performing machining operations directly at the work site, eliminating the need to transport large equipment to a workshop. This cost-effective and time-saving approach is commonly employed in industries such as oil and gas, power generation, mining, and marine services. Whether you're a professional in the field or simply interested in understanding the fundamentals of on-site machining, familiarizing yourself with key terms used in this industry is essential. In this blog post, we will explore some of the key terms associated with on-site machining operations.

Portable Machining Tools:

Portable machining tools are compact and versatile machines designed to perform various machining operations on-site. These tools are specially engineered to be lightweight and easily transported to the work site. They often include devices such as portable milling machines, portable lathes, flange facers, line boring machines, and portable drilling machines.

Line Boring:

Line boring is a precision machining process used to enlarge, repair, or align the inside diameter of a cylindrical hole. It is commonly employed to restore the alignment of large machinery components like engine blocks, gearboxes, and turbine casings. Line boring machines are used to accurately cut new bearing surfaces or realign existing ones.

Flange Facing:

Flange facing is the process of machining the mating surfaces of a flange to ensure proper alignment and sealing. Portable flange facers are used to create smooth and precise surfaces on flanges, ensuring a leak-free connection when joined with other flanges or fittings.


Milling is a machining process that involves removing material from a workpiece using rotating cutting tools. Portable milling machines enable on-site machinists to perform tasks such as milling keyways, drilling holes, and machining complex shapes on large components like turbine casings and pump bases.


Turning is a machining operation that involves rotating a workpiece while a cutting tool removes material from its surface to create cylindrical shapes. Portable lathes are commonly used for on-site turning operations, allowing machinists to repair or modify large shafts, rollers, and other cylindrical components.


Drilling is the process of creating holes in a workpiece using a rotating cutting tool called a drill bit. Portable drilling machines are versatile tools used in on-site machining to drill precise holes in various materials, including metal, concrete, and composites.

Cold Work:

The  cold cutting metal is used in environments where the presence of ignition sources is strictly prohibited. By employing a deliberate reduction in cutting speed and utilizing pneumatic motors, the work is conducted in a manner that prioritizes safety, eliminating the potential for sparking. Air motors are frequently favored over electric motors in situations where spark generation is a concern. A key advantage of cold cutting is the absence of a heat affected zone, thereby safeguarding the integrity of the workpiece from thermal distortion or damage.

Machining Tolerances:

Machining tolerances refer to the allowable deviation in dimensions during the machining process. These tolerances determine the level of accuracy required for a specific component or assembly. On-site machinists must understand and adhere to specified tolerances to ensure precise and reliable results.

Surface Finishing:

Surface finishing involves improving the quality and appearance of machined surfaces. Portable tools such as grinding machines and polishers are used to achieve desired surface finishes, removing imperfections and creating smooth and visually appealing surfaces.

As on-site machining continues to play a crucial role in various industries, understanding the key terms associated with this field becomes increasingly important. Whether you're a professional in the industry or simply interested in expanding your knowledge, familiarizing yourself with terms such as portable machining tools, line boring, flange facing, milling, turning, drilling, machining tolerances, and surface finishing will help you grasp the fundamentals of on-site machining operations. By having a solid understanding of these key terms, you'll be better equipped to comprehend the techniques and processes involved in on-site machining, opening up new opportunities for growth and expertise in this specialized field.