Onsrud 52-300 5/16 inch two flute routing end mill plunge point 3 inch

Application Scope

The Onsrud 52-300 is a solid router bit designed for plunge cutting in MDF and wood. Its two-flute spiral upcut geometry clears chips upward while the plunge point allows direct entry into the workpiece. This tool suits CNC operators and woodworkers who need a dedicated upcut bit for grooving, pocketing or profiling in sheet goods and solid timber. Buyers who need downcut or compression spirals for double-sided laminates cannot use this bit.

Practical Limits

The upcut action pulls chips away from the cut but can lift thin or lightly clamped material, so secure hold-down is essential. The spiral geometry is optimised for the listed primary materials; cutting abrasive composites, plastics or non-ferrous metals may reduce edge life or cause overheating. California Proposition 65 requires awareness that the product contains a chemical known to cause reproductive harm, so appropriate personal protection and ventilation should be used.

Installation Notes

The bit installs in any collet or tool holder that accepts the 5/16 inch shank, with no proprietary adapters required. Common issues include insufficient collet grip leading to slippage, excessive stick-out causing vibration, and feeding too fast for the two-flute chip load which can break the cutting edges. Proper tool-length setting and a conservative plunge rate prevent most premature failures.