An upholstery hammer is a lightweight hammer

Hammer

A hammer is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, forging metal and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. The usual features are a handle and a head,...

 used for securing upholstery

Upholstery

Upholstery is the work of providing furniture, especially seats, with padding, springs, webbing, and fabric or leather covers. The word upholstery comes from the Middle English word upholder, which referred to a tradesman who held up his goods. The term is equally applicable to domestic,...

 fabric to furniture frames using tacks

Thumbtack

A drawing pin , thumbtack , or push pin is a short nail or pin with a circular, sometimes domed, head, used to fasten items such as documents to a wall or board for display. Various designs and names are used. They are inserted and removed by hand, hence the terms "thumbtack" and "push pin"...

 or small nails.

Usually, one face of the hammer is magnetized to aid in placement of tacks. Once started, the tacks are driven with the other face. To apply tacks rapidly an upholsterer will hold tacks in the mouth and spit them onto the magnetized face of the hammer.

Staple gun

Staple gun

A staple gun or powered stapler is a hand-held machine used to drive heavy metal staples into wood, plastic, or masonry. Staple guns are used for many different applications and to affix a variety of materials, including insulation, house wrap, roofing, wiring, carpeting, upholstery, and hobby and...

s have largely replaced tacking as an upholstery technique.