Facing
Creating a flat surface perpendicular to the workpiece axis.
Process Steps
1. Tool Setup
Position facing tool at center height and perpendicular to workpiece axis.
2. Speed Selection
Set appropriate RPM based on workpiece diameter. Speed must be reduced as tool moves toward center.
3. Initial Facing
Begin cuts slightly off center, feeding outward. Take progressive depth cuts.
4. Center Facing
Carefully face across center, maintaining consistent feed rate.
5. Final Passes
Make light finishing cuts for best surface finish and accuracy.
Material-Specific Guidelines
Mild Steel
- • Good chip formation at moderate speeds
- • Minimal burr formation with sharp tools
- • Coolant recommended for larger diameters
Recommended Speeds: 80-90 SFPM for HSS tools, 250-350 SFPM for carbide
Tooling Notes: Use tools with 5-10° side cutting edge angle for better chip control
Stainless Steel
- • Reduce speed near center to prevent work hardening
- • Consistent feed rate critical
- • Higher cutting forces near outer diameter
Recommended Speeds: 50-60 SFPM for HSS tools, 120-200 SFPM for carbide
Tooling Notes: Positive rake geometry recommended, use rigid tool holders
Brass/Bronze
- • Excellent surface finish possible
- • Minimal cutting fluid needed
- • Watch for sharp edges/burrs
Recommended Speeds: 100-150 SFPM for HSS tools, 300-400 SFPM for carbide
Tooling Notes: Zero or negative rake tools prevent chatter
Quality Control Specifications
Perpendicularity
Method: Dial indicator on faced surface
Tolerance: 0.001" per inch typical
Frequency: First piece and periodic checks
Surface Finish
Method: Visual and surface roughness gauge
Tolerance: 63-125 microinch typical
Frequency: Every part visual, sample measurement
Face Flatness
Method: Precision straight edge and feeler gauges
Tolerance: 0.002" typical
Frequency: Setup and periodic checks
Length
Method: Depth micrometer or height gauge
Tolerance: ±0.005" typical
Frequency: Every part
Operation Difficulty
Basic
Safety Guidelines
- • Ensure workpiece is properly secured in chuck
- • Start cuts from the center and move outward
- • Use appropriate speeds for workpiece diameter
- • Watch for long spiral chips during facing
- • Keep tool perpendicular to workpiece axis
Required Tooling
Facing Tool
Right-hand turning tool ground with proper clearance angles for facing operations
Dial Indicator
For checking perpendicularity of faced surface
Surface Gauge
For checking flatness of faced surfaces
Machinist Square
For verifying perpendicularity to workpiece axis
Troubleshooting Guide
Uneven Surface
Check tool height, ensure it's exactly at center. Verify feed rate is consistent
Poor Finish at Center
Reduce speed as tool approaches center, maintain steady feed rate
Not Square to Axis
Check tool perpendicularity and compound rest alignment
Concave/Convex Face
Ensure cross slide is exactly perpendicular to spindle axis
Pro Tips & Tricks
Center Facing
Start cuts slightly off-center and feed outward to prevent center pip formation. Alternate direction on final passes.
Best for: All facing operations, critical for precision faces
Speed Control
Reduce spindle speed as tool approaches center. Consider using CSS mode on CNC lathes.
Best for: Larger diameter workpieces, finish facing
Tool Alignment
Set tool exactly at center height and perpendicular to workpiece axis. Use precision square during setup.
Best for: All facing operations, especially for precision work
Burr Control
Use a slight chamfer on the outer edge before final facing cuts to minimize burr formation.
Best for: Production facing, finish requirements