Swaging offers high productivity and excellent connection reliability, but is difficult to re-work. Therefore, it is important to optimize the process conditions at the time of mass production. Shown below are the representative control factors that affect the quality of swaging.

(1)Swaging quality

The quality of swaging can be represented by the following items.

a） Swage strength (Slip torque) b） Appearance (Cracks, Bow deformation, Shaft deformation)

Explanations

	a) Swage strength ---	Slip and torque determined by deformation resistance, when pins (rivets) are inserted in pin holes and deformed, are evaluated. This is largely influenced by the materials of both components, naturally.
	b)Appearance ---	This is a quality control item of swage quality indirectly determined by visually inspecting the appearance of the swaged part, in order to avoid any negative effects on assemble operation.

(2)Swage quality control factors

Swage quality control factors are explained by classifying into 4Ms (1st M: Material, 2nd M: Machine, 3rd M: Methods, 4th M: Man).

1) Material/Parts related control factors

	(1)	Workpiece material characteristics (Relationship of two material characteristics - - Tensile strengths, elastic modulus differentials)
	(2)	Shape and accuracy of both parts swaged (Plate thickness, swaging amount, swage-crushed size, shaft swaging shape, burrs, etc.)
	(3)	Workpiece pre-processing state (Heat treatment - - Hardness, surface treatment - - Friction coefficient, surface layer strength, hardness, etc.)

2)Machine related control factors

	(1)	Swage drive characteristics of swaging equipment (Operational stability, Workpiece locating accuracy, Looseness, etc.)
	(2)	Swaging punch shape (Punch angle, Tip shape, etc. - - - - Transmission of deformation stress and its stability)

3)Swaging methods related control factors

	(1)	Pressurizing method (Fixed dimensional pressurization method, Fixed load pressurization method) and pressurization force
	(2)	Pressurization conditions (Presence or absence of heating, pressurization speed, etc.)

4)Operating personnel (Man) related control factors

	(1)	Stability of pressurization operation (pressurization forces, Force application time)
	(2)	Equipment maintenance