The most basic tools used by gunsmiths are hand tools. Screwdriver sets are required for putting the different pieces together. Wrenches are needed, the most important of which are a full set of Allen wrenches or hex keys. Ball peen hammers are required to hammer out imperfections in the metal. You will also need a brass and nylon hammer for hammering imperfections out of finer materials. Several files are needed, including a 6- and 10-inch mill file and an 8-inch pillar file. You will also need highly specialized pliers.
As with any trade, you will need safety equipment when performing gunsmithing. Gloves are needed when welding parts together. Leather sleeves protect your arms from welding sparks. You will also need a face shield for welding tasks. Safety goggles should always be worn when gunsmithing. Hearing protection is needed not just for testing the guns, but also to protect your ears when you are working on the guns.
You won't be able to make professional-quality firearms with hand tools alone. You will also need machine tools to work with metals. Gunsmiths must know how to use lathes and milling machines. In addition, you will need to know how to use the various attachments to the milling machines, like reamers and borers.
Professional gunsmithing is a precision trade. You will need measuring tools that provide you with exact measurements of your work. Inside and outside micrometers provide measurements of round metalwork to thousandths of an inch. Inside and outside calipers similarly provide precision length measurements.
You will need a set of vice grips to secure your work to a bench. Further, a bench mat will keep your bench from being damaged when working on a gun. C clamps are another tool helpful for securing your work.