Annular Cutter Pilot Pins

Annular Cutter Pilot Pins

Persistools annular cutter pilot pins are precision steel accessories used together with HSS and TCT annular cutters for accurate hole positioning and stable drilling.

Because annular cutters remove material only around the circumference of the hole, a center pilot is required to guide the cutter accurately at the beginning of the drilling process.

The pilot pin extends beyond the cutting edge of the annular cutter and contacts the workpiece first, helping establish the hole center before the cutter teeth engage.

Accurate Center Positioning

At the start of drilling, the pilot pin helps:

• Locate the drilling center
• Reduce cutter wandering
• Improve hole-position accuracy
• Stabilize cutter engagement
• Support cleaner hole entry

This is especially important when using larger-diameter annular cutters or drilling on smooth steel plate surfaces.

Slug Ejection After Breakthrough

The pilot pin also works as an ejector for the center slug left inside the annular cutter.

As the cutter completes the hole, the spring-loaded or supported pilot pin pushes against the center material and helps eject the slug from the cutter.

This reduces the need for manual removal and improves the efficiency of repeated hole-making operations.

Because the pilot pin protrudes beyond the annular cutter, it also maintains contact with the material during the final stage of breakthrough, helping keep the cutting process controlled until the hole is completed.

Steel Construction for Repeated Use

Pilot pins are commonly manufactured from hardened or wear-resistant steel.

The steel construction provides:

• Good toughness
• Resistance to repeated impact
• Stable dimensional accuracy
• Reliable spring and ejecting action
• Long service life under normal drilling conditions

Although pilot pins are consumable accessories, their wear rate is generally lower than that of the annular cutter itself.

Matched to Cutter Diameter and Cutting Depth

Different annular cutters require different pilot pin sizes.

The correct pilot pin depends mainly on:

• Cutter diameter
• Cutting depth
• Cutter type
• Shank / arbor system
• Machine configuration

Longer annular cutters require correspondingly longer pilot pins to maintain the correct extension beyond the cutting edge.

Persistools can supply pilot pins for both TCT and HSS annular cutters, including standard and custom lengths.