Wrenches are used with threaded fasteners like bolts and nuts. A bolt has external threads while a nut has internal threads and this thread pattern combination allows them to lock together and act as fasteners. Nuts come in a variety of configurations including wing nuts which provide appendages that allow tightening and loosening by hand, slotted nuts that use a cotter pin to lock the nut in place and prevent it from loosening, and lock nuts that also prevent loosening via nylon in their threads. Threads are identified by pitch which is the number of threads per inch.

Screwdrivers come in many different handle, shaft, and tip configurations for use in a wide variety of applications. Screwdrivers are classified by their tip which is shaped to fit a corresponding screw head. Common tips are slotted (flat) and Phillips (x-shaped).

Rulers are used to both measure distance and to draw straight lines. Tape measures are flexible rulers useful for measuring longer distances and in tighter spaces. Rulers and tape measures provide similarly accurate measurements.

When you start sawing by creating a kerf it will help prevent the saw from slipping sideways when you begin the power strokes that do most of the cutting.

Welding is a high-temperature process that involves melting the base metals in the objects to be joined to fuse them together. A filler metal is used to provide additional material to make up a joint that, depending on the weld type, can be stronger than the base materials alone. Oxyacetylene welding is a welding process that uses a torch fueled with oxygen and acetylene gases. Electric-arc welding utlizes electric current in a safer welding process (it doesn't involve burning explosive gases) that enables a wide variety of specialized applications like stick, MIG (metal inert gas), and TIG (tungsten inert gas) welding.