FAGNNU4921-S-K-M-SPSuper Precision Double Row Cylindrical Roller Bearing — 105 mm ID Tapered Bore, 145 mm OD, 40 mm Width, SP, Brass Cage, C1

Product Description

What this part is:

FAG NNU4921-S-K-M-SP super-precision double-row cylindrical roller bearing, type NNU, for machine-tool spindles. Bore 105 mm (small end of taper), outside diameter 145 mm, width 40 mm. Tapered bore 1:12. Non-locating, separable design with ribs on the outer ring. Lubrication groove and holes in the outer ring. One bearing.

Decoding the designation:

NNU4921 — double-row NNU type, 49 dimension series; bore code 21 = 105 mm.

S — lubrication groove and holes in the outer ring.

K — tapered bore, taper 1:12.

M — machined brass cage.

SP — Schaeffler super-precision tolerance class.

Specifications:

Bore Diameter: 105 mm. Outside Diameter: 145 mm. Overall Width: 40 mm. Number Of Rows: 2. Bore Type: Tapered 1:12. Rolling Elements: Cylindrical Roller. Dynamic Load Rating: 130,000 N. Static Load Rating: 260,000 N. Fatigue Load Limit: 34,500 N. Limiting Speed: 5,500 rpm grease; 6,500 rpm oil. Operating Temperature: -30 to 150°C. Internal Clearance: C1. Precision Class: SP. Cage Material: Machined brass. Item Weight: 1.95 kg (4.30 lb). Lubricant: grease or oil through the outer-ring groove (3.2 mm holes, 6.5 mm groove width). GTIN: 4012801580427. Unit Quantity: 1 Pc.

Dimensions and mounting:

Permissible axial displacement: 2 mm. Inner ring raceway diameter (F): 118 mm. Shaft shoulder diameter: 117 mm. Housing shoulder diameter: 134 mm. Minimum chamfer: 1.1 mm. Maximum recess radius: 1 mm.

Compatibility and replacement:

Current Schaeffler designation NNU4921-S-K-M-SP replaces NNU4921SK.M.SP. SKF NNU 4921 BK/SPW33 has the same size, tapered bore and lubrication-groove configuration.

Frequently asked questions:

What are the size and bore type of the FAG NNU4921-S-K-M-SP?

Bore 105 mm, outside diameter 145 mm, width 40 mm, with a 1:12 tapered bore.

What do the S, K, M and SP letters mean?

S is a lubrication groove and holes in the outer ring, K a 1:12 tapered bore, M a machined brass cage and SP the Schaeffler super-precision tolerance class.

What are the load ratings and speed limits?

Dynamic load rating 130,000 N, static load rating 260,000 N, limiting speed 5,500 rpm on grease and 6,500 rpm on oil.