H3 Series Adapter Sleeves

H3 Series adapter sleeves are mechanical components for mounting bearings with 1:12 tapered bores onto cylindrical shafts. The sleeve provides the tapered bearing seat while its cylindrical bore fits the shaft, allowing the bearing to be positioned and secured without machining a matching taper on the shaft.
The H3 range covers sleeve sizes from H304 to H322, corresponding to shaft diameters from 17 mm to 100 mm in the stated range. A standard assembly consists of a slotted steel sleeve, a matching KM-series locknut, and an MB-series locking washer. 

The following table provides representative dimensions from the stated H3 range. The exact bearing and locking components should be matched to the selected sleeve designation. 

For production orders, dimensional drawings for the specific sleeve designation should be used rather than relying on representative dimensions. 

H3 adapter sleeves are intended for bearings with 1:12 tapered bores. Depending on the sleeve size, applications can include:

• Self-aligning ball bearings with tapered bores
• Spherical roller bearings with tapered bores
• Other bearing types using a compatible 1:12 tapered bore

The sleeve designation should be selected together with the bearing designation. Check the bearing's bore diameter, taper, internal clearance and manufacturer's mounting requirements before ordering.

Not every tapered-bore bearing is compatible with every H3 sleeve. Bearing and sleeve dimensions should be matched individually.

The H3 sleeve has a longitudinal slot and an external 1:12 taper. During mounting, axial movement of the bearing along the taper produces the required radial expansion of the sleeve and establishes the interference fit between the sleeve and shaft.
The standard locking arrangement consists of:

• Slotted adapter sleeve
• Matching KM-series locknut
• MB-series locking washer

The locknut is used to drive the bearing into position on the taper. After the required mounting position or internal clearance reduction has been reached, the locking washer secures the locknut against rotation. 

The adapter sleeve allows a tapered-bore bearing to be installed on a cylindrical shaft, reducing the need for a machined tapered shaft seat. However, the shaft seating still requires suitable dimensional and geometric accuracy.

Before ordering, verify:

• Shaft diameter and tolerance
• Shaft roundness and cylindricity
• Shaft surface condition
• Bearing bore and taper
• Required bearing internal clearance
• Available axial mounting space

The original specification refers to shaft tolerances in the h9–h11 range for certain applications. Actual tolerance requirements depend on the bearing arrangement and operating conditions and should therefore be confirmed against the applicable bearing manufacturer's mounting recommendations.

A typical mechanical mounting procedure is:

Clean the components
Remove contamination from the shaft, sleeve and bearing mating surfaces.

Position the sleeve
Place the adapter sleeve on the cylindrical shaft at the required approximate axial position.

Install the bearing
Position the bearing on the tapered outside surface of the sleeve.

Drive the bearing onto the taper
Tighten the matching locknut and move the bearing axially along the taper until the specified mounting position or internal clearance reduction is achieved.

Secure the locknut
Bend or engage the locking washer as specified for the applicable locknut and sleeve arrangement.

For bearings where internal clearance is critical, the mounting procedure should follow the bearing manufacturer's specified clearance reduction or drive-up method. Locknut tightening by feel alone should not be used as a substitute for the specified mounting procedure. 

The stated standard material is carbon structural steel / 20# steel. Surface treatment and corrosion protection depend on the sleeve size and production specification.
The supplied specification states:

• Surface roughness: Ra ≤ 2.5 μm
• Phosphated finish: specified for sizes up to bore size 40
• Larger sizes: rust-preventive protection

Material grade, heat treatment and surface condition should be confirmed against the technical specification for the required H3 size when these factors are part of the purchasing requirement. 

Dimensional inspection focuses on the features that directly affect bearing fit and installation:

• Shaft-side bore diameter
• Bearing-side internal diameter
• External taper
• Overall sleeve length
• Thread dimensions
• Locknut and locking washer compatibility
• Slot condition and burr control

The stated inspection methods include calibrated gauges, micrometers, taper gauges and air gauging. Inspection requirements can be specified according to the dimensional and application requirements of the order.

H3 adapter sleeves can be used in bearing arrangements for:

• Industrial gearboxes and speed reducers
• Conveyor and material-handling equipment
• Agricultural machinery
• Mining and crushing equipment
• Textile machinery
• Paper-processing equipment
• Industrial shaft and bearing housing assemblies

They are particularly suitable for arrangements where a tapered-bore bearing needs to be mounted on a cylindrical shaft.

H3 adapter sleeves can be supplied as complete assemblies with the corresponding locking components, subject to the selected size and configuration.

Available supply information can include:

• H3 sleeve designation
• Matching locknut
• Matching locking washer
• Technical drawing
• Dimensional information
• Industrial packaging

For an RFQ, provide the H3 sleeve designation or bearing designation, shaft diameter, quantity and any specific material, surface-treatment or packaging requirements. A bearing model number or existing sleeve designation can also be provided for compatibility checking.