Field Machining for Keyways

field machining milling slot for keyway
Field machining services can help create keyways on-site for critical rotating machinery.

Rotating equipment plays a critical role in plant operations. Keyways are often essential for the normal functioning of these types of machinery. However, there may be challenges that need the creation or repair of the keys. That’s why we provide field machining to create or repair keyways for your equipment. This allows you to get the services you need for equipment that are difficult or impractical to send to the shop. During installation or maintenance, our seasoned specialty millwright technicians may find the need to add a keyway to rotational equipment at your facility. In this article, we will discuss on-site machining for keyways.

What are Keyways?

Keyed joints are made up of keys and keyways. A key is a machining component found in rotating equipment that attaches a rotating element to a shaft. It intercepts movement and relative rotation between the part and shaft to allow torque transmission. To correctly operate, the shaft and rotating component should have a keyway.

On the other hand, a keyway is a slot in a hub in which a key fits into. In many cases, field machining may be needed for keyways if the machine is crucial for operations or is unrealistic to move. Industrial plants that employ on-site keyway machining include the following:

  • Oil and gas facilities
  • Water treatment plants
  • Power plants
  • Coal processing plants
  • Metalworking
  • Manufacturing and production plants

Keyway Field Machining

Keyway field machining is a unique offering that a field machinist and welder can perform. It involves cutting, shaping, or fabricating materials to serve an intended design. It’s common to discover the need for keyway field machining during specialty millwright services, such as installation or maintenance for rotating equipment.

When is Field Machining Needed for Keyways?

There are many situations that may require field machining for keyways. For example, some include:

  • Emergency repairs
  • System adjustments and maintenance
  • Equipment installations

Keyway Field Machining Options

Keyway machining in the field involves using high-precision machines to modify or repair key slots or cut-out assemblies. There are many solutions for cutting keyways. Our field machinists may choose different options to cut keyways in your shaft and coupling hubs, including:

Keyway Broaching for Speed

Through a broaching machine, our field machinists eliminate more material in the shaft or coupling hub to create a keyway. The broaching machine’s sharpened teeth eliminate material quickly. Because of this, the machinist can cut a keyway in just one to three strokes. 


Using an internal keyway slotting equipment for a keyway involves the removal of material through a sequence of tooth cutting strokes. It gives great flexibility for large and specialty keyways.

Wire EDM

Wire EDMs are commonly used for small quantity runs that need precision. They remove material through electrical discharge machining.  Also, wire EDMs operate at 12″ an hour and are therefore not suitable for quick machining needs. 

Shaping for Blind Keyways

Blind keyways are those that don’t go across the whole length of the shaft. Shaping utilizes a single tooth cutting tool. Shaper cuts don’t have the same accuracy as keyseater cuts. This is because shapers aren’t guided down a fixed post for the cut. Therefore, it’s essential to get precise tolerance inspections. Broaching and wire EDMs are not tailor-made to handle blind keyways.

Field Machining: Milling for Shaft-Only Keyways

Much like shaping, milling lets us cut fractional length, straight or tapered keyways. This is preferable for cutting external shaft keyways on site. 

Quality Mechanical Services from Leverage Mechanical

At Leverage Mechanical, we are a full-service shop. Our team offers various services for industrial infrastructures, such as specialty millwright services, valve rebuild services, and machining services for industrial applications serving in our locations all over Louisiana and Texas. We aim to be your greatest asset by offering reliable, cost-effective solutions that meet your needs. Contact us today and let our team get the job efficiently and economically done.