Pneumatic joining machine with manual shifting or the loader for any kind and shape of frames, either with four sides. The mitered pieces of mouldings to be joined are connected tightly by a steel nail. Nailing unit for nails type NP (for not too hard and hard woods and compact materials as MDF) or type PV (for very soft, soft, not too hard woods and plastic). The loaders are interchangeable in the same machine. The machine may be used in tilled position that allows the operator to work from machine front or rear side. It is possible to set nails in many different positions and to insert more nails one behind the other in each position. Standard with horizontal clamp and adjustable guide. Sound level: LAeq < 70.1 dB (A).