New Inventory Daily | Same Day Free Shipping

13k+ reviews

FafnirMM318KSuper Precision Deep Groove Ball Bearing, 90 x 190 x 43 mm, 63 Heavy Series, P4S Precision Class, Open

Condition: New

Availability:

1 in stock

Categories: ,

Super-precision deep groove ball bearing, 90 x 190 x 43 mm, P4S (ABEC 7/9), open, CN clearance, 63 heavy series. Chrome steel, metric.

List Price

$468.74

1 in stock

Prefer eBay? Buy this item on our store (opens in a new tab)

Small green outline icon of a shipping box with a clock, indicating delivery time
Availability

1 in stock

On the Shelf & Ready to Ship

Green shield badge reading "Same-Day Shipping" with box and delivery truck icons
Free Shipping

On all orders

Green shield icon with box and arrow graphic labeled "Free Returns"
Free Returns

No Risk, No Hassle

Specifications

Key Specifications

MFR / BrandFafnir
MPNMM318K
ModelMM-318-K / 6318 / P4S / ABEC 7-9
Bearing TypeBall Bearing
ID90 mm
OD190 mm
Width43 mm

Technical Specifications

MaterialChrome steel
Base Number6318
Industry Termssuper precision ball bearing; spindle bearing; ABEC 7 deep groove; precision deep groove bearing; machine tool bearing
Application TypesPrecision spindles; grinding and boring heads; precision gearboxes; instrument drives
Bore Shaft Size90 mm
Mpn VariantsMM318K; MM-318-K; MM 318 K; M318K; M-318-K; MM318; 318K
Manufacturer StatusLegacy Fafnir designation; Fafnir super-precision production passed to The Timken Company
Number Of Rows1
Part NumberMM318K
SeriesFafnir MM300 super-precision / ISO 63 heavy dimension series
Seller Part Number: B-BC2#4NCRTQ

Product Description

What this part is

Fafnir MM318K super-precision deep groove ball bearing. Bore: 90 mm. Outside Diameter: 190 mm. Overall Width: 43 mm. Base Number: 6318. Precision Class: P4S (ABEC 7/9). Series: 63 heavy dimension series. Number Of Rows: 1. Rolling Elements: Balls. Closure Type: Open. Internal Clearance: CN (normal). Material: Chrome steel. Design Units: Metric. Fafnir super-precision production passed to The Timken Company.

Decoding the designation

MM is Fafnir’s super-precision spindle-bearing prefix and carries Precision Class P4S, ABEC 7/9.

The 3 gives the 63 heavy dimension series. The 18 is the bore code, giving a 90 mm bore and the 6318 envelope at 90 x 190 x 43 mm.

K is a Fafnir configuration suffix. Searchable forms: MM318K, MM-318-K, MM 318 K, M318K, M-318-K, MM318, 318K.

What these specs mean in practice

A super-precision deep groove bearing carries radial load with modest thrust in either direction while holding the running accuracy of a spindle bearing. P4S holds bore and outside diameter tolerance, width variation and radial and axial runout to close limits, so the shaft runs truer and the assembly generates less vibration at speed. That suits grinding and boring spindles, precision gearboxes and instrument drives.

The 63 heavy series carries more load in the same bore than the equivalent 62 or 60 series, being wider and larger in outside diameter with bigger balls. It trades speed capability and radial space for capacity.

CN clearance is the normal internal clearance range, the general-purpose setting for a shaft and housing at standard interference fits.

Quantity and configuration

Unit Quantity: 1 Pc. Single row, open on both faces.

Interchange guidance

Base Number: 6318, 90 x 190 x 43 mm. Legacy Fafnir MM numbers cross to Timken’s later super-precision numbering. A commercial-grade 6318 shares the same envelope at a coarser tolerance class. A 6314 at 70 x 150 x 35 mm is a related size. Also written MM318K, MM-318-K, MM 318 K, M318K, M-318-K, MM318 and 318K.

You May Also Like

RHP 6004TBP4 Bearing 20x42x12 mm 6004 T/TB P4 MM-9104-K England

$51.32

5 in stock

Add to cart
Deep Groove Ball Bearing — 65 mm ID, 120 mm OD, 23 mm Width, ABEC 5, Open, CN Clearance

$45.69

23 in stock

Add to cart
Deep Groove Ball Bearing - Straight Bore, 15 mm ID, 32 mm OD, 9 mm Width, Steel Shields Both Sides, C4 Internal Clearance
6002ZZC4

$7.57

28 in stock

Add to cart

Need help finding the right part?

Our team can locate, cross-reference, and source all parts.

Assortment of MRO parts including motor, bearing, gears, cylinder and valve

News

Replacement PCBs for Legacy CNC: A Field Guide

Siemens put a number on the bad day you’re having.

Sell Surplus Servo Drives: Who Actually Buys in Bulk

Rockwell’s own product page for the Kinetix 6000 is down

Additional Resources

Need help finding the right part?

Our team can locate, cross-reference, and source all parts.

Get In Touch
Need help finding the right part?

Our team can locate, cross-reference, and source all parts.

Get In Touch

Sort

Brand

Price

MPN

Categories

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.