Metal Ceramic Cold Saw Blade Tooth Geometry Structure, Burr-

Metal ceramic cold saw blades adopt TiCN-based cermet cutting tips to realize low-temperature cutting of solid round bars, stainless steel and alloy steel profiles. Improper tooth geometry design will lead to extrusion burrs, tip chipping, poor surface finish and short service life. This paper optimizes the overall tooth geometric structure of metal ceramic cold saw blades, analyzes the burr suppression mechanism of different tooth forms, and forms a complete set of rotational speed and feed parameter matching process to achieve burr-free precision cutting of various metal profiles.

1. Formation Mechanism of Cutting Burrs in Metal Ceramic Cold Sawing

1.1 Extrusion flash burr at cutting outlet

When saw teeth cut through the bottom of the workpiece, uncut metal produces plastic flow under the extrusion of rake face, forming obvious flash burrs. Traditional straight teeth have large extrusion contact area, which is the main cause of heavy burrs.

1.2 Built-up edge adhesion burr

Friction heat between tooth surface and workpiece generates metal built-up edge, scratching the cutting surface to form irregular serrated burrs. Unreasonable chip breaker groove leads to poor chip removal and aggravates adhesion burrs.

1.3 Vibration chatter ripple burr

Unreasonable clearance angle causes flank friction with the workpiece, and cutting vibration creates ripple burrs on the section, seriously affecting dimensional accuracy of finished cut pieces.

1.4 Uneven tooth load tearing burr

Mismatched rake and clearance angles result in inconsistent cutting load of each tooth. Partial overloaded teeth pull metal and form rough tearing burrs at cutting edges.

2. Optimized Tooth Geometry Structure Design of Metal Ceramic Cold Saw Blade

The core tooth structure includes rake angle, double clearance angle, chip breaker groove, tooth pitch, tooth tip micro chamfer and arc transition, which jointly determine burr suppression effect and cutting stability.

2.1 Graded rake angle design for different workpieces

Mild steel solid bars: Positive rake angle 8°~12°, sharp cutting edge reduces plastic extrusion deformation and outlet burrs;

Stainless steel and alloy structural steel: Slight positive rake angle 3°~6°, balancing sharpness and impact resistance to avoid cermet tip chipping;

High-hardness alloy steel and bearing steel: Zero rake angle 0°, improving tip compression resistance to prevent tooth breakage under heavy cutting load.

2.2 Double-layer anti-friction clearance tooth structure

Combined structure with primary clearance angle 12°~16° and secondary fine clearance angle 25°. The primary clearance avoids flank scratch on cutting surface; the secondary large clearance reduces contact area between tooth back and workpiece, eliminates vibration ripple burrs and improves surface finish.

2.3 Arc chip breaker groove for burr suppression

Arc chip breaker grooves are set on rake face. Metal chips are bent and broken instantly by grooves during cutting, reducing long strip chip winding and built-up edge adhesion. Arc transition without sharp corners prevents cracking of cermet tips, balancing chip removal and tool service life.

2.4 Tooth tip micro chamfer structure for anti-chipping and burr reduction

0.1~0.3mm micro chamfer is ground at sharp tooth tip corners. The chamfer disperses cutting impact force to prevent tip collapse; meanwhile, the flat chamfer compresses the workpiece outlet edge to restrain large flash and form neat burr-free cutting edge.

2.5 Variable tooth pitch vibration reduction layout

Alternating wide and narrow tooth pitches avoid fixed-frequency cutting resonance and greatly reduce vibration amplitude, effectively eliminating periodic ripple burrs on sections, which is essential for high-precision burr-free cutting.

3. Complete Burr-Free Precision Cutting Parameter Matching Process System

Optimized tooth structure must be matched with saw blade rotational speed, workpiece feed speed and single-tooth cutting depth to fully exert burr suppression performance.

3.1 Linear speed matching rules by workpiece material

Mild steel solid bars: Linear speed 100~140m/min, high-speed thin cutting to reduce metal extrusion deformation;

304/316 stainless steel: Linear speed 60~90m/min, properly reduce speed to lower cutting temperature and avoid built-up edge adhesion burrs;

40Cr, 45# alloy steel: Linear speed 70~110m/min, balancing cutting efficiency and tip wear resistance;

Alloy steel above HRC35: Linear speed 40~60m/min, low-speed heavy cutting to prevent tip chipping.

3.2 Feed rate and single-tooth cutting depth control standard

Single-tooth feed fz=0.04~0.08mm for burr-free processing. Excessive feed causes strong extrusion and heavy flash burrs; too small feed increases friction heat and built-up edge. Segmented variable feed is adopted: low feed speed at workpiece penetration and exit positions, constant medium feed in the middle cutting stroke to eliminate outlet burrs fundamentally.

3.3 Auxiliary matching of cutting cooling parameters

EP cold cutting fluid is adopted to fully flush the cutting zone. Sufficient cooling reduces cutting temperature, inhibits metal thermal adhesion burrs, and lubricates flank to reduce friction ripple burrs. Nozzles align with tooth tip cutting position to avoid dry friction cutting.

3.4 Auxiliary optimization of saw blade diameter and tooth number matching

Small-diameter cold saw blade 200~300mm: 60~80 teeth, fine tooth density suitable for thin bar burr-free cutting;

Medium-diameter cold saw blade 350~450mm: 40~60 teeth, universal tooth number for conventional solid steel cutting;

Large heavy-duty cold saw blade above 500mm: 30~40 teeth, thickened tip structure for large-size bars, matched with low feed speed to control burrs.

4. Common Burr Defects Caused by Mismatched Tooth Structure & Cutting Parameters and Countermeasures

4.1 Heavy flash burr at workpiece cutting outlet: Too small rake angle and excessive single-tooth feed; increase positive rake angle, reduce fz and set low feed speed at exit stroke.

4.2 Serrated adhesion burr on cutting surface: No chip breaker groove and insufficient cutting fluid supply; add arc chip breaking structure and strengthen full coverage flushing of cold cutting fluid.

4.3 Periodic ripple vibration burr: Uniform equal tooth pitch and unreasonable clearance angle parameters; replace variable pitch tooth layout and adjust double-layer clearance angle parameters.

4.4 Local irregular tearing burr: No micro chamfer on tooth tip and uneven load of each tooth; grind tooth tip micro chamfer and optimize graded rake angle by material.

4.5 Burrs accompanied by tip chipping: Excessive positive rake angle and high cutting linear speed; properly reduce rake angle and lower saw blade linear cutting speed.

5. Acceptance Inspection Standard for Burr-Free Cutting

1. Burr height at cutting edge ≤0.02mm, no obvious flash visible to naked eyes;

2. Cutting surface roughness Ra ≤1.6μm, free of vibration ripple scratches;

3. Continuous cutting test of 500 workpieces, no obvious burr increase and no tooth tip chipping;

4. Chips are fully formed and easy to break, no long strips winding on tooth surface to form built-up edge.

Conclusion

The burr-free cutting performance of metal ceramic cold saw blades fundamentally relies on optimized tooth geometry including graded rake angle, double anti-friction clearance, arc chip breaker groove, tooth tip micro chamfer and variable pitch vibration reduction layout. Combined with material classified matching of linear speed, single-tooth feed and full cooling auxiliary process parameters, three burr sources of extrusion, adhesion and vibration in cold sawing are comprehensively suppressed. This integrated process of tooth design and parameter matching can realize stable burr-free precision cutting of various metal bars, remove secondary deburring procedures and improve overall production efficiency of metal cutting.