H-3138 adapter sleeve: complete specifications & mounting data
The H-3138 is an adapter sleeve sized 190 x 240 x 141 mm (tapered bore x sleeve OD x width) for a plain 170 mm metric shaft with M 190x3 thread supplied with the KM 38 lock nut at 10,500 g per ISO 2982-1. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 190 mm |
| Outer diameter D | 240 mm |
| Width B | 141 mm |
| Fits shaft diameter | 170 mm |
| Sleeve thread G | M 190x3 |
| Included lock nut | KM 38 |
| Included locking device | MB 38 |
| Associated hydraulic nut | HMV 38 E |
| Material | Carbon_Steel |
| Mass | 10500 g |
| Manufacturer designation | H 3138 |
| Standard | ISO 2982-1 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 23.1 adapter sleeves for metric shafts |
| Last verified | 2026-09-30 |
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.
Dimensions in inches & H31-series range
| Bore d | 7.48 in |
|---|---|
| Outer diameter D | 9.449 in |
| Width B | 5.551 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 25 mm |
| Smallest bore in H31-series | 100 mm |
| Largest outer diameter in H31-series | 250 mm |
| Width range across H31-series | 76–150 mm |
| Bore position in H31-series (smallest first) | 10 of 11 |
| Bore above smallest H31-series size | 90 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| H | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
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-3138 model number is decoded
this sleeve mounts a bearing with a 190 mm tapered bore onto a plain 170 mm shaft; the 240 mm outside diameter and 141 mm width define the tapered seat the bearing is driven onto mass 10,500 g is 55.3 g per mm of bore; the sleeve with its KM 38 nut and MB 38 washer forms the complete 141 mm-wide mounting assembly a width-to-bore ratio of 0.74 gives a 141 mm tapered contact length; the longitudinal slit lets the sleeve close down radially, so the grip on the 170 mm shaft is purely frictional 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 38 nut on the M 190x3 thread advances 3 mm and takes out roughly 0.25 mm of clearance the sleeve wall is 25 mm thick at the small end — 13.2% of the 190 mm bore — thin enough to contract evenly onto the 170 mm shaft while keeping the seat round under the clamping load the 170 mm shaft diameter puts this at the heavy end of the metric range, where the catalogue recommends the HMV 38 E hydraulic nut to reach drive-up without damaging the thread the H prefix names the basic metric adapter sleeve: a slit 1:12-taper bush supplied complete with the KM 38 lock nut and MB 38 locking washer — bending one washer tab into a nut slot secures the assembly dimensionally this sleeve belongs to the large-size H 31 range for 231..K spherical roller bearings; the 240 mm OD and 141 mm width follow the ISO 2982-1 boundary plan for that series the delivery includes the KM 38 lock nut and the MB 38 locking washer, and the HMV 38 E hydraulic nut is the associated drive-up tool typical applications include conveyor pulley and drum bearing seats, woodworking saw and planer spindles and industrial fan and blower impeller shafts adapter sleeves earn their place wherever a tapered-bore bearing must sit at any axial position on a plain shaft — here a 190 mm bore bearing on a 170 mm shaft in industrial fan and blower impeller shafts the sleeve lets the designer use a plain, unstepped shaft and still locate the bearing positively; only one shoulder is needed, opposite the KM 38 nut ordering digest — H 3138: 170 mm plain shaft to 190 mm tapered bore, sleeve 240 mm OD and 141 mm wide, thread M 190x3, supplied with KM 38 nut with MB 38 washer, drive-up tool HMV 38 E; listed mass is 10,500 g
Typical equipment & failure modes
Common applications
- pump shafts in water and process plants
- conveyor pulley and drum bearing seats
- gearbox input and output shafts
- agricultural machinery axle and PTO shafts
Known failure patterns
- reusing a stretched locking washer tab invites fatigue failure; the bent tab snaps off and the nut backs off undetected
- a plain KM nut used without its MB washer has no anti-rotation feature and will unthread under vibration
- misaligning the slit with the load zone or belt-pull direction concentrates stress on the split; orient the slit away from the main load
- interchanging nut families (KM vs KMFE, MB vs MS) across executions loses locking reliability even when the thread appears to fit
- neglecting the catalogue axial displacement value leaves the bearing either loose on the taper or preloaded hot in service
Selection pitfalls — read before you substitute
- reusing a stretched locking washer tab invites fatigue failure; the bent tab snaps off and the nut backs off undetected
- misaligning the slit with the load zone or belt-pull direction concentrates stress on the split; orient the slit away from the main load
- bending more than one washer tab to force alignment work-hardens both tabs; choose the single closest slot only
Frequently asked questions
What shaft size does the H-3138 adapter sleeve fit?
H 3138 is listed for a 170 mm plain shaft; its tapered bore accepts 190 mm K-suffix bearings, the sleeve measures 240 mm OD and 141 mm wide.
What does the H 3138 designation mean?
H 3138: H-series metric adapter sleeve in the H31 dimension plan; the code resolves to a 190 mm tapered bore and a 170 mm shaft.
What is supplied with the H-3138?
Supplied hardware is the KM 38 lock nut and MB 38 locking washer. Drive-up is done with the HMV 38 E hydraulic nut.
How much does the H-3138 adapter sleeve weigh?
It weighs 10,500 g; the figure is the sleeve-only catalogue mass, with the KM 38 nut counted on the same product row but the hydraulic tool ordered separately.
How is the H-3138 mounted on the shaft?
Slide the sleeve onto the 170 mm plain shaft against the abutment, fit the bearing, turn the KM 38 nut with a hook spanner until the measured clearance drop matches the table, and lock it with one MB 38 tab.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 23.1 adapter sleeves for metric shafts on 2026-09-30. Read our editorial & correction policy.