Reaming is a finishing operation for high-precision holes using multi-edge tools. High penetration rates and small cutting depths produce high surface finishes, excellent hole quality and tight dimensional tolerances.
Initial Considerations for Reaming Operations
When performing reaming operations, there are several parameters that need to be considered that affect the reamer tool life:
Depth of cut
Speed and feed
Workpiece material
Run-up
Offset
Coolant pressure and concentration
Intermittent cuts
Workpiece clamping
Geometry and grade
Tool length
Correct toolholder
General tips for reaming
To achieve the best results when using reamers, they must be allowed to "work." Leaving too little stock in preparation for reaming is a common mistake. If insufficient stock is left in the hole before reaming, the reamer will rub, quickly wear and cause diameter loss. Not leaving too much stock is equally important to performance.
Select the best reamer type for the application and the best reaming speed and feed. Make sure the pre-drilled hole is the correct diameter
The workpiece must remain rigid and there should be no play in the machine spindle.
The chuck must be of good quality. If the reamer slips in the chuck and feeds automatically, reamer breakage can occur
Keep tool overhang from the machine spindle to a minimum
Use the recommended lubricant to extend tool life and ensure that fluid reaches the cutting edge. Since reaming is not a heavy cutting operation, a 40:1 dilution of soluble oil is usually satisfactory. Air blasting can be used on gray cast iron if machining dry.
Do not allow the reamer's chip flutes to become clogged with chips
Before re-grinding the reamer, check concentricity between centers. In most cases, only the bevel leads need to be reground
Keep the reamer sharp. Frequent re-grinding is a good economic benefit, but it is important to understand that the reamer only cuts on the bevel and taper leads, not on the edge faces. Therefore, only these leads need to be re-grinded. Re-grinding accuracy is important for hole quality and tool life