NSK7018CTYDUMPA7Angular Contact Ball Bearing Pair, Super Precision — NSK 7018CTYDUMPA7, 90x140x24 mm, 15° Contact Angle, Medium Preload, Ball-Guided Cage, 2 Pcs

Product Description

What this part is:

NSK 7018CTYDUMPA7 is a universally ground pair of single-row super-precision angular contact ball bearings from the 70 series. Bore Diameter: 90 mm. Outside Diameter: 140 mm. Overall Width: 24 mm. Contact Angle: 15°. Rolling Elements: Ball. Bore Type: Straight. Closure Type: Open. Number Of Rows: Single Row. Bearing Material: Bearing Steel. Series: 70 Series. Base Number: 7018C.

Dynamic Load Rating: 90,500 N per bearing. Static Load Rating: 69,000 N per bearing. Limiting Speed: 10,000 rpm grease; 15,300 rpm oil. Item Weight: 1.16 kg (2.56 lb) per bearing. Load ratings and mass are quoted per bearing, not for the set.

Decoding the designation:

7018 — 70 series super-precision angular contact ball bearing on a 90 mm bore.

C — 15° contact angle.

TY — ball-guided cage.

DU — duplex universal pair, ground so the two bearings mount back-to-back, face-to-face or in tandem.

M — medium preload class.

PA7 — an NSK internal accuracy designation.

What these specs mean in practice:

The 15° contact angle biases capacity toward radial load and lifts the speed ceiling relative to steeper 25° and 30° angles, which is why the C angle dominates machine-tool spindle work. Preload: Medium (M). Cage Type: Ball-guided. Lubricant: Grease or oil / oil-air.

A ball-guided cage centres itself on the rolling elements rather than on a ring land, which removes cage-to-land rubbing and suits arrangements where lubricant reaches the cage pockets freely. Universal grinding means the offset ground into each ring face sets the preload automatically once the pair is clamped, without shims or spacers. Medium preload raises axial and radial rigidity over the light class in exchange for additional heat generation.

Mounting data:

Effective load centre a: 27.4 mm. Permissible axial load Pa: 44.5 kN. Minimum shaft abutment diameter da: 99 mm. Maximum housing abutment diameter Da: 131 mm. Maximum housing abutment diameter Db: 134 mm. Maximum shaft fillet radius ra: 1.5 mm. Maximum housing fillet radius rb: 0.8 mm. Minimum chamfer dimension r: 1.5 mm. Minimum chamfer dimension r1: 1 mm. Recommended grease quantity: 6.2 g per bearing.

Quantity and configuration:

Unit Quantity: 2 Pcs. Mounting Arrangement: Duplex universal pair (DU).

Cross-references:

NSK 7018CTYNDUMP4 is the closest match, a medium-preload 15° duplex pair with a polyamide ball-guided cage. NSK 7018CTRDUMP4Y, RHP 7018CTDUMP4 and Fafnir 2MM9118WI-DUM are the same pair with a phenolic outer-ring-guided cage. SKF 7018 CD/P4A, FAG B7018-C-T-P4S, Koyo 7018C, NTN 7018CG/GNP4 and GMN S 6018 C are 15° bearings of this size sold as singles.