H-3120 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-3120 model number is decoded

the 10 mm difference between the 90 mm shaft and the 100 mm nominal seat diameter is bridged by taper contraction as the slit sleeve closes during drive-up, rather than by machining the shaft the seat taper is 1:12, so each millimetre of axial drive-up removes about 1/12 mm of radial clearance; one turn of the KM 20 nut on the M 100x2 thread advances 2 mm and takes out roughly 0.167 mm of clearance the M 100x2 thread spans about 38.0 nut turns across the 76 mm width; each indexed turn is a measurable drive-up step when setting the bearing clearance on the 100 mm seat the annular envelope between 100 mm bore and 130 mm OD is about 5,419 mm² in cross section, which sets the 1,800 g mass at steel density for the 76 mm-long slit bush the OD-to-bore ratio is 1.30: the 130 mm sleeve OD is only 15 mm of section beyond the 100 mm seat, leaving room for the bearing outer ring without enlarging the housing bore at 90 mm shaft the sleeve suits mid-size machinery — conveyor pulleys, industrial fans and gearbox output shafts carrying 100 mm bore bearings reading H 3120: H marks the standard sleeve execution, the size code encodes the 100 mm tapered bore, and the kit includes the KM 20 nut plus MB 20 washer for positive locking the H31 designation block places it in the large-size H 31 range for 231..K spherical roller bearings — every sleeve in the block uses the same bore-code logic, and here the 100 mm tapered bore matches the K-suffix bearing it is ordered for hardware on this row: the KM 20 lock nut and the MB 20 locking washer; SKF lists the HMV 20 E hydraulic nut for mounting and dismounting typical applications include industrial fan and blower impeller shafts, marine winch and deck machinery shafts and pump shafts in water and process plants adapter sleeves earn their place wherever a tapered-bore bearing must sit at any axial position on a plain shaft — here a 100 mm bore bearing on a 90 mm shaft in pump shafts in water and process plants the sleeve lets the designer use a plain, unstepped shaft and still locate the bearing positively; only one shoulder is needed, opposite the KM 20 nut ordering digest — H 3120: 90 mm plain shaft to 100 mm tapered bore, sleeve 130 mm OD and 76 mm wide, thread M 100x2, supplied with KM 20 nut with MB 20 washer, drive-up tool HMV 20 E; listed mass is 1,800 g

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• interchanging nut families (KM vs KMFE, MB vs MS) across executions loses locking reliability even when the thread appears to fit
• over-driving the taper eliminates bearing internal clearance entirely; clearance reduction must be measured with feeler gauges, not estimated from nut torque
• neglecting the catalogue axial displacement value leaves the bearing either loose on the taper or preloaded hot in service