A metal file is usually a hand tool but can also be used in a power filing machine. The file consists of a handle and the filing surface, which can be a variety of shapes and sizes. The type of handle used with the file depends on the user's comfort and the application itself. Handles can be easily interchanged. The filing surface has abrasive teeth that smooth rough edges when rubbed over the application's finish. Applications that frequently require metal files include jewelry making, tooling, molding and die casting.

Metal files are commonly hardened steel. The file's surface must be harder than the surface it's filing or the file and the user will both suffer wear and tear. The file's surface is smooth, second-cut, bastard, coarse or rough, with rough having the most abrasive teeth. When purchasing a metal file, consider the following:

1. Use a diamond-coated metal file on extremely hard surfaces.

2. Purchase specialty machinist files for use in filing machines.

3. Order needle files for precision work and soft surfaces.

4. Smooth corners and tight spaces with a riffler metal file.

Action Steps
The best contacts and resources to help you get it done

Purchase a diamond-coated metal file

Diamond-coated metal files, also referred to as diamond files, use industrial diamonds embedded into the file's surface to smooth finishes. This type of file is for hard surfaces such as stone and hardened steel. You can purchase nearly every style of file with a diamond coating.

I recommend: Find a general-use diamond-coated metal file at Diamond Drill Bit & Tool. This file is ideal for finishing edges on glass, stained glass, ceramic, stone, marble, fiberglass and plastic. PFERD offers diamond files for ultra-hard surfaces, including hardened tool steel, exotic metals, ceramics, tungsten carbide and glass.

Find metal file providers for machinery

Machinist metal files are used in filing machines. A filing machine is a power tool typically used in specialty tooling applications to reduce worker fatigue and ensure product consistency. Machinist files are for use in both parallel and reciprocating filing machines.

I recommend: Browse the metal file list of machinist files at Federal File Company. The metal file provider offers parallel and reciprocating machinist files, some of which are diamond coated. TESSCO offers an eight-piece machinist file set, which includes a file cleaner and pouch.

Order a needle metal file

Metal needle files are typically used in industries that require precision and perfection, such as jewelry making. This type of file creates extraordinary finishes, but the process of using a needle file can be time consuming. You can also use needle files in woodworking and other soft surface applications.

I recommend: Browse a large inventory of needle files at The Contenti Company. The company designs tools specifically for jewelry making. Gyros Precision Tools sells individual needles files as well as needle file sets. Most of these files are capable of leaving flawless finishes on soft materials.

Use a riffler metal file

Metal riffler files are curved and are ideal for filing in tight or awkward spaces. This type of file is also for use to file curved edges. Injection molding applications frequently require riffler files to smooth out a cavity's surface before injecting the molding material.

I recommend: Shor International offers a large inventory of riffler files. Every file is double ended. Find a set of 10 double-ended riffler files at Electron Microscopy Sciences. This set is available for purchase online.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Many metal files are sold without handles, which must be purchased separately. Unless being used in a machine, always use metal files with a handle to avoid injury. Check the supplier's metal file information to see if the handle is included.