MRC1908R4STStainless Angular Contact Ball Bearing – 40 mm Bore x 62 mm OD x 12 mm Width, 15°, ABEC 5, 440C

Product Description

What this part is

MRC 1908R4ST single-row angular contact ball bearing in stainless steel, with a counterbored outer ring. Bore: 40 mm. Outside Diameter: 62 mm. Overall Width: 12 mm. Contact Angle: 15°. Precision Class: ABEC 5. Number Of Rows: 1. Rolling Elements: 440C stainless steel balls. Bore Type: Straight. Closure Type: Open both faces. Material: AISI 440C stainless steel rings and rolling elements. Unit Quantity: 1 Pc.

Decoding the designation

1900 — MRC’s extremely light series. The section between bore and outside diameter is the thinnest MRC builds in this family, which is what puts a 40 mm shaft inside a 62 mm housing bore.

08 — the bore code. Multiplied by five it gives Bore: 40 mm.

R — Contact Angle: 15°, with a counterbored outer ring. The counterbore admits a full ball complement past a low shoulder, and the high shoulder opposite is what takes the thrust.

ST — AISI 440C stainless steel rings and rolling elements, through-hardened martensitic stainless. The bearing resists corrosion in its own right rather than relying on a plating or a coating.

What these specs mean in practice

Contact Angle: 15° is the shallow end of the angular contact range. It gives the highest speed capability of the family and the lowest heat generation, and it suits a moderate one-direction thrust rather than a heavy one — exactly the trade a high-speed spindle wants. Precision Class: ABEC 5 tightens bore and outside diameter tolerance and, more importantly, radial and axial runout, so shaft position becomes a specification rather than a consequence. Material: AISI 440C stainless steel makes the bearing suitable for washdown, food, marine and instrument service where a chrome steel bearing would corrode. Bore: 40 mm. Outside Diameter: 62 mm. Overall Width: 12 mm.

Quantity and configuration

Unit Quantity: 1 Pc. One single-row bearing, straight bore, open on both faces, counterbored outer ring.

Fitting notes

The high-shoulder side of the outer ring faces the thrust load, so the bearing is fitted with the counterbore turned away from the direction the axial force arrives from. Mounting force is applied through the ring being fitted and is never transmitted across the balls. A precision-class bearing expects ground and measured shaft and housing seats and clean handling. 440C runs slightly softer than chrome steel, so seats are checked for burrs before the bearing goes on.

Interchange guidance

40 x 62 x 12 mm is the 7908 envelope and the carton carries the 7908 cross itself. A 7908 C is the 15° execution and matches on angle, so the substitution question reduces to class and material: an interchange has to be ABEC 5 or tighter and, where corrosion is the reason the part is there, stainless.

Searchable variants

1908R4ST, 1908-R4-ST, 1908 R4 ST, 1908RST, 7908, MRC 1908R4ST.