688A

Extra Small Ball Bearings and Miniature Ball Bearings Metric Series

688A

Extra Small Ball Bearings and Miniature Ball Bearings Metric Series

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Parts Number
688AMC5

Product Information

Display units Metric Imperial

Parts Number

688AMC5

Boundary Dimensions

d	8	mm	Bore diameter
D	16	mm	Outside diameter
B	4	mm	Width
r (min.)	0.2	mm	Chamfer dimension

Basic Load Ratings

Cr	1770	N	Basic dynamic load rating
C0r	710	N	Basic static load rating

Speeds

Grease	36000	min-1	Grease lubrication
Oil (Oil-bath)	43000	min-1	Oil-bath lubrication

Abutment and Fillet Dimensions

da (min.)	9.6	mm	Diameter of shaft abutment
Da (max.)	14.4	mm	Diameter of housing abutment
ra (max.)	0.2	mm	Radius of shaft or housing fillet

Additional information

z	9		Number of Balls
Dw	2.381	mm	Ball Diameter

Mass

Mass approx.

0.00312

Mass approx.

CAD

FAQs (3)

Customer Questions

What are radial loads and axial loads?

Loads are defined by their direction. Loads perpendicular to the shaft are called radial loads and loads parallel to the shaft are called axial (thrust) loads.

How do deep groove ball bearings (DGBBs) differ from single-row angular contact ball bearings?

While DGBBs can handle axial loads in both directions, single-row angular contact ball bearings can only receive axial load in one direction.

What are the differences between open, sealed, and shielded deep groove ball bearings?

Seals and shields offer additional protection for bearing components and help to improve and maintain lubrication. In terms of sealing performance, sealed bearings rank best, followed by shielded bearings, then finally open bearings.
NSK uses supplementary designations D, DU, DW, and V (DD, DDU, DDW, VV) for sealed bearings and Z (ZZ) for shielded bearings. No supplementary designations are listed for open bearings.

Drawing for Reference

Designations	Basic Load Ratings		Radial Internal Clearance			Tolerance Class	Limiting Speeds		Number of Balls	Ball Diameter		Mass
Designations	Cr (N)	C0r (N)		min	max	Tolerance Class	Grease (min-1)	Oil (Oil-bath) (min-1)	Number of Balls	(mm)	(inch)	(kg)
688A	1770	710				P0	36000	43000	9	2.381	0.09374	0.00312

Not to scale.
(*) The chamfer dimensions are minimum values.
684A, 684AZZ1, 629, 629ZZ, 629XX, 629DD : Chamfer dimensions are not based on ISO 15.

More Information

More Information
NSK Product Type2	ESM_MD
NSK Product Type	Bearing

Extra Small Ball Bearings and Miniature Ball Bearings Metric Series

Extra Small Ball Bearings and Miniature Ball Bearings Metric Series

Parts Number

Boundary Dimensions

Basic Load Ratings

Speeds

Abutment and Fillet Dimensions

Additional information

Mass

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