H-304-E adapter sleeve: complete specifications & mounting data

Specification table

Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 23.1 adapter sleeves for metric shafts) · extracted 2026-09-30

Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 23.1 adapter sleeves for metric shafts); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.

Cross references & equivalents

Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.

How the H-304-E model number is decoded

the M 20x1 thread spans about 28.0 nut turns across the 28 mm width; each indexed turn is a measurable drive-up step when setting the bearing clearance on the 20 mm seat the KMFE 4 lock nut carries size index 4, matching the bore-code family of the 20 mm seat; the nut engages the M 20x1 sleeve thread over its full width a width-to-bore ratio of 1.40 gives a 28 mm tapered contact length; the longitudinal slit lets the sleeve close down radially, so the grip on the 17 mm shaft is purely frictional the annular envelope between 20 mm bore and 38 mm OD is about 820 mm² in cross section, which sets the 47 g mass at steel density for the 28 mm-long slit bush the OD-to-bore ratio is 1.90: the 38 mm sleeve OD is only 9 mm of section beyond the 20 mm seat, leaving room for the bearing outer ring without enlarging the housing bore with a 17 mm shaft this sleeve serves the small-bearing end of the series — fans, small gearboxes and light conveyor rollers where a plain shaft keeps cost down H 304 E belongs to the E execution: the KMFE 4 nut has an integral grub-screw lock that bears on the sleeve thread, so there is no washer tab to bend and no tab slot to align as part of the medium-section H 3 range, the default seat for 13..K and 22..K self-aligning ball bearings and 222..K spherical roller bearings, this size keeps series-standard proportions: 28 mm width on a 20 mm bore, so the bearing lands at the catalogue axial position the KMFE 4 lock nut ship in the kit, and no hydraulic accessory is required at the 17 mm shaft size typical applications include woodworking saw and planer spindles, agricultural machinery axle and PTO shafts and marine winch and deck machinery shafts adapter sleeves earn their place wherever a tapered-bore bearing must sit at any axial position on a plain shaft — here a 20 mm bore bearing on a 17 mm shaft in marine winch and deck machinery shafts the sleeve lets the designer use a plain, unstepped shaft and still locate the bearing positively; only one shoulder is needed, opposite the KMFE 4 nut ordering digest — H 304 E: 17 mm plain shaft to 20 mm tapered bore, sleeve 38 mm OD and 28 mm wide, thread M 20x1, supplied with KMFE 4 self-locking nut; listed mass is 47 g

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• greasing the tapered seat or shaft destroys the dry friction the joint relies on; a lubricated taper can let the whole sleeve spin under load
• driving the bearing via the outer ring during mounting loads the rolling elements; force is always applied through the lock nut on the inner ring
• mounting without a fixed abutment lets the bearing walk axially; the sleeve needs a shaft shoulder opposite the lock nut