NTN7408G/GLP5Single Row Angular Contact Ball Bearing 40x110x27 mm Heavy 74 Series ABEC 5 Light Preload

Product Description

What this part is

A single row angular contact ball bearing in the 74xx heavy dimension series, 40 mm bore, 110 mm outside diameter, 27 mm width, held to P5 tolerance. The 74 series is the heaviest of the single row angular contact series: for a given bore it uses a larger outside diameter and larger balls than the 72 or 73 series, which buys load capacity and stiffness at the cost of speed and radial envelope.

Decoding the designation

In the NTN scheme 74 is the heavy angular contact dimension series and 08 the ISO bore code, five times eight giving the 40 mm bore. GL is the light preload class. P5 is the tolerance class, equivalent to ABEC 5, which NTN also writes as B5 in its own precision scheme — a 7408T1B5 is the same tolerance class expressed the other way. The preload code implies universal grinding, so two pieces of the same designation assemble as a matched pair, back-to-back, face-to-face or tandem, without shims.

Axial load direction

Angular contact geometry inclines the ball contact line to the radial plane, so a single row carries radial load together with axial load in one direction only, resolved through the high shoulder on one side of each ring. Axial load in both directions requires two bearings mounted opposed. Two mounted in tandem double the capacity in one direction without adding the other.

What these specs mean in practice

The heavy 74 series suits positions where axial load dominates and where deflection under that load has to stay small — worm gear input shafts, screw drives, heavy machine tool feed positions and vertical spindles. Light preload removes internal clearance and raises stiffness and running accuracy while keeping frictional heat and the speed penalty to a minimum; heavier preload classes buy stiffness and cost speed.

Precision class

P5 corresponds to ABEC 5, tightening bore, outside diameter, width and radial and axial runout well beyond a normal-class bearing, though one grade below the P4 / ABEC 7 used for high-speed grinding spindles. At this class the shaft and housing seat tolerances become part of the achieved accuracy.

Quantity and configuration

1 Pc. Single bearing, open on both faces, with no seals, shields or snap ring. Supplied without a spacer set, lock nut or preload sleeve.

Interchange guidance

The 40 x 110 x 27 mm envelope in the 74 heavy series is served by other makers as 7408 in their own precision codes. Contact angle, preload class and tolerance class are each part of the specification: a same-envelope 7408 at a different preload class or a different cage is a related size rather than a substitution. A 7308 or 7208 shares the 40 mm bore in a lighter section, with a smaller outside diameter and a different rating, so it is a related size and not an interchange.