IKO BA44 Shell Type Needle Roller Bearing, Inch Series, 6.35 x 11.112 x 6.35 mm

IKO BA shell type needle roller bearings are the inch series, caged, with no inner ring. This page lists 61 sizes: 6.35 to 50.8 mm (1/4 to 2 in) shaft, 11.112 to 60.325 mm (7/16 to 2 3/8 in) outside diameter and 6.35 to 38.1 mm wide.

Shell type needle roller bearings are lightweight with large load ratings. The outer ring is drawn from thin special steel plate, carburised and quenched, and gives the lowest sectional height of the needle roller bearings. They are press-fitted into the housing, so no fixtures for axial positioning are needed, and suit mass-produced products where economy matters.

In the model number the two figures after BA are the shaft diameter and the width in sixteenths of an inch, so BA1216 is a 3/4 in shaft and a 1 in wide bearing. Where the shaft cannot be hardened and ground, use an IRB inner ring (see the sizes table).

Where this product is used

• Inch size shafts in mass-produced assemblies
• Press-fit housings with no axial fixing
• Compact shaft supports with a very low sectional height

Features

• Shell type caged needle roller bearing, inch series (BA), 61 sizes
• Shaft 6.35 to 50.8 mm (1/4 to 2 in), outside diameter 11.112 to 60.325 mm (7/16 to 2 3/8 in)
• Thin drawn outer ring with the lowest sectional height of the needle roller bearings, pressed into the housing with no axial fixing
• Basic dynamic load ratings 1.51 to 52 kN, static 1.12 to 113 kN
• Allowable rotational speed 6,000 to 55,000 rpm (oil lubrication)

Key specifications

Available sizes

A dash in the inner ring column means no inner ring is listed for that size. Fw is the roller set bore diameter, D the outside diameter and C the width; C and C0 are the basic dynamic and static load ratings, and speed is the allowable rotational speed.

Selecting the right option

Choose the size with the Size (Shaft x O.D. x Width, mm) option, which gives the shaft diameter, outside diameter and width of each bearing in millimetres. The model number is shown with each variant and in the sizes table.

Other shell type series: BA is the standard inch series and BHA the heavy duty inch series. For metric shafts see TLA, TA and TLA UU.

Shell type bearings have no inner ring. If the shaft cannot be hardened and ground, pick the IRB inner ring shown against the size in the sizes table.

Fitting and use

For a steel or cast iron housing, use a shaft tolerance of h6 and a housing bore tolerance of J7. The shaft and housing limits for each size are in the specifications under each variant.

The shaft acts as the raceway: its surface hardness should be 58 to 64 HRC and its surface roughness 0.2 µmRa or less. Where the shaft cannot be hardened and ground, use an inner ring (IRB). The required static safety factor is usually more than 3.

Press the bearing gently into the housing with a suitable tool, with the marked end surface up. The outer ring is thin, so never strike it directly with a hammer. It is fitted with interference, so it does not need axial fixing.

These bearings are not prepacked with grease, so lubricate them before use. The allowable rotational speed in the tables is for oil lubrication; for grease lubrication use up to 60% of it. None of these models has an oil hole. An oil hole version of the shell type is made by adding OH to the end of the number.

Related products

Parts that go with this range: BHA: the heavy duty inch series; IRB inner rings for a shaft that cannot be hardened and ground; TLA: the standard metric series.