The difference between the straight shank and fixed shank

2025-09-08

1. Straight Shank

Definition: The shank of the tool is cylindrical with a consistent diameter.
Features:
- Common size: diameter is equal to or slightly smaller than the cutting part.
- Usage: held in a chuck or collet and fixed by friction.
- Widely used for small-diameter drills, end mills, and other tools.
Advantages: Versatile, easy to change, and offers good machining accuracy.
Disadvantages: Limited torque transmission, not suitable for large-diameter tools.

2. Fixed Shank

Definition: The shank and cutting part are integrated into a single piece; it cannot be removed or replaced.
Features:
- One-piece design (not interchangeable like replaceable-head tools).
- Common in solid carbide end mills, welded tools, and small-diameter cutters.
Advantages:
- High rigidity and stability, no risk of tool head loosening.
- Good torque transmission, suitable for high-speed and high-precision machining.
Disadvantages:
- Once worn, the whole tool must be discarded, leading to higher costs.
- Less flexible than modular tools.

✅ Summary:

Straight shank refers to the shape of the shank (cylindrical, uniform diameter).
Fixed shank refers to the structural design (shank and cutting part are one solid piece).

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