1. High Carbon Steel Ensures Longevity and Strength.
2. Second-cut grade is great for deburring, shaping, and sharpening.
3. Double-cut teeth creates a smooth finish on interior contours and holes.
4. Precision Milled, Tempered and Coated Teeth provide durable cutting and good performance.
5. Large, comfortable handle gives you a comfortable grip for controlled pressure.
6. Mill File is a versatile machinist file for working with metal, plastic, and wood. suitable for garages, factories, engineering, workshop and DIY useSpecifications:
Product Name: Flat File
Material: Steel, Plastic
Total Length: 140mm / 5.51-inch
Shank Size: 3mm / 0.12-inch; File Teeth Width: 6.2mm / 0.24-inch
File Grade: Second Cut; File Teeth: Double Cut
Package Content: 20 x Flat Files
Weight: 197g;

Do not try to file hardened steel with a hardened steel file; you will quickly ruin the file. Also diamond-embedded files should not be used on soft materials, including many soft steels, as this will cause the diamonds to be torn out. Clean out any bits of file metal with a stiff wire brush.

Chalk/oil/lard the file: rub a small amount of oil into the teeth of the file to:
1. Make cutting easier from the loss of friction of metal on metal
2. Remove the chance of having pins to form and stick in the teeth
3. Keep the dust down and make cleanup so as to breath much easier
4. Rust protection on the piece and the file itself.
Using Oil, do not forget that requires the surface to be clean.