Abstract: A hand-held pneumatic yarn splicing device has a splicing chamber into which a pair of yarn ends to be spliced together may be placed, the chamber having at least one air inlet extending into the chamber for directing air from a high pressure source external of the device into the chamber. The chamber is interchangeable with other chambers and has a pair of projections extending from the wall of the chamber to break up the twist of highly twisted and heat set yarns which are to be spliced together by the action of the high pressure air. The chamber is cylindrical and has a center axial bore and the projections extend radially from the inner wall of the chamber.