Square File
A four-sided file with sharp, square edges for filing slots, keyways, and square-cornered openings.
What is it?
The square file has four flat faces meeting at sharp corners, designed for filing rectangular slots, keyways, and internal square corners where a flat file cannot reach.
What is it used for?
- Filing rectangular slots and keyways
- Squaring internal corners
- Shaping square holes and notches
Common sizes
- Tapered and blunt forms
- Lengths from 4 to 12 inches
- Four flat faces with sharp corners
How to choose
Choose a square file where four flat faces and sharp corners are needed, such as slots and keyways. Match cut grade to material and finish.
Anatomy
Understanding the parts of a square file helps you use, maintain, and buy it with confidence.
- Faces: the four flat cutting surfaces
- Corners: the sharp edges for square-cornered work
- Point: the leading taper
- Tang: the handle mount
Materials & construction
Hardened high-carbon steel with teeth cut at a controlled angle; case-hardened so the sharp corners and faces retain their bite.
Safety & maintenance
- Always fit a handle
- Push forward to cut, lift on the return
- Clean packed teeth with a file card
- Wear safety glasses; corners can shed sharp fragments
Also known as
square file, keyway file