"Why is the brightness of this stainless steel part inconsistent? And the life of the milling cutter is only half that of others!」

- Is this your real confusion on the shop floor?

Many engineers' first reaction is, "Coating is not good?" "The accuracy of the machine tool has dropped?" …

But the truth may be more basic: your milling cutter spiral angle is not chosen right at all!

1. Why is the spiral angle an "invisible killer"?

The spiral angle, a seemingly ordinary parameter on this tool drawing, is actually the core of controlling the direction of cutting force, chip removal efficiency, and vibration resistance!

Low helix angle (e.g. 35°): The cutting force is more radial, the tool body strength is high, suitable for intermittent cutting of cast iron (such as engine blocks), and the impact resistance is strong.

High helix angle (such as 45°): The cutting force is more axial, the vibration is light, and the chip evacuation is smooth, especially suitable for stainless steel, titanium alloy and other viscous materials to avoid chips scratching the processed surface.

✅ Brief note: the more "sticky" the material and the higher the required finish, the larger the helix angle!

2. Real cases: the difference of one knife is a world of difference in cost

A customer used a brand of 40° spiral angle milling cutter to process 304 stainless steel valve body:

Single tool life: 200 pieces

Surface finish: Ra 1.6μm (slight grain in some areas)

We recommend switching to a Walter 45° helical angle mill + AH7045 coating:

Lifespan increased to 380 pieces (almost doubled!) ）

Surface finish stabilization Ra 0.8μm (mirror effect meets the standard at one time)

? Key Insights:

When cutting stainless steel, the high helix angle allows the "chips to leave the workpiece faster" and avoid repeated scratching! At the same time, the proportion of axial force is increased, which reduces vibration and makes the machine tool spindle work more "quietly".

ThreeWalterA must-see for machine tool users: the technical pitfalls of grinding high helix angles

Grind your own high helix angle mill? Watch out for these pits!

The grinding wheel must be sharp: when the helix angle is > 40°, the arc length of contact between the grinding wheel and the cutting edge increases, which is easy to heat up. Must useDiamond grinding wheel+ High-frequency sharpening (Walter RCS software automatically monitors passivation values).

Coolant nozzle angle: the grinding point must be accurately aligned! If the deviation is > 5°→ the microscopic heat of the cutting edge rises sharply→ the tool life is directly "cut in half".

Anti-collision warning: High helix angle tools have small space in the chip chamber, so Walter ToolStudio's 3D simulation function is required for programming to avoid interference between the grinding wheel and the tool body.

4. How to quickly self-check?

Take out the milling cutter on your site and judge against it:

Processing cast iron/Hardened steel→ Prefer 35°-40° helix angle (anti-chipping edge)

Processing stainless steel/aluminum alloy/titanium alloy→ decisively select the spiral angle above 45° (re-debris)

Processing composite materials → even more than 50° (avoid delamination)