Press Fit Surface Smoothness

Reduces the efficient interference. Since you rarely determine the real surface smoothness value, use its maximum value in the calculation, so that surface smoothness of both contact surfaces reduces the height of unevenness to half. Surface smoothness greatly depends on the surface shape, which is determined by the machining method. It is small for ground surfaces. Surface smoothness values in calculations are entered in [mm] or [in]. The recommended surface smoothness is calculated using the formula:

H = R zA + R zB ≅ 4 (R aA + R aB )

where:

	R_zA	unevenness height of hole surface of external part
	R_zB	unevenness height of shaft surface of internal part
	R_aA	surface texture (mean arithmetic deviation) of external part hole
	R_aB	surface texture (mean arithmetic deviation) of internal part shaft