Internal circlips are retaining rings for securing mechanical elements (e.g. bearings) in bores. Circlips are installed into a groove and creating a shoulder that retains the assembly. Lugs with holes are provided for easy fitting and removal with pliers.

Metric internal circlip dimensions are shown in the following chart according to DIN 472 standard.

Some important notes from the DIN 472 standard:

- Material: C 67 , C 75 or Ck 75 spring steel in accordance with DIN 17222.

- Finish: Circlips must be without burr. Circlips are normally supplied corrosion-proof. Details are given in DIN 472.

- Designation: Bore diameter (nominal dimension) and circlip thickness s (Ex: Circlip DIN 472 - 40 x 1,75)


Circlip Type
Bore Diameter (d1)


Internal Circlips - Metric DIN 472
Parameter Symbol Value Unit
Nominal Bore Diameter d1 --- mm
Clip Thickness of the Circlip s ---
Thickness Upper Deviation sup_dev ---
Thickness Lower Deviation Slow_dev ---
External Diameter of Circlip
(Not under tension)
d3 ---
External Diameter
Upper Deviation
d3_up_dev ---
External Diameter
Lower Deviation
d3_low_dev ---
Maximum Radial
Width of the Lug
amax ---
Beam (Radial Width of
Circlip Opposite the Aperture)Note 1
b ≈ ---
Diameter of Lug Holes d5_min ---
Weight of 1000 pieces w ≈ --- kg
Groove Groove Diameter d2 --- mm
Groove Diameter
Upper Deviation
d2_up_dev  ---
Groove Diameter
Lower Deviation
d2_low_dev ---
Groove Width m ---
Groove Depth with Nominal
 Sizes of d1 and d2
t ---
Minimum Edge Margin nmin ---
Data Note 2
Minimum Symmetrical Diameter of
Bore during Fitting
d4 ---
Load-bearing Capacity of Groove at a Yield
 Point of the Grooved Material of 200 MPa
FN --- kN
Load-bearing Capacity of Circlip with
Sharp-edged Abutment of the Pressure Part
FR ---
Edge Chamfering Distance of the
Surface abutting the Circlip
g --- mm
Load-bearing Capacity of Circlip for
Abutment with Edge Chamfering Distance g
FRg --- kN
Nominal Size of Pliers according to DIN 5254 --- --- ---

Note 1 : Dimension b shall not exceed dimension a max.

Note 2 : Supplementary data is applicable only to circlips in spring steel in accordance with DIN 17222.

Note 3 : The load-bearing capacities (FN, FR, FRg) contain no safety against yielding under static stress nor against fatigue fracture under fluctuating stress.

Note 4 : Details of load-bearing capacities calculation for different parameters are given in DIN 472.

  • DIN 472 , Circlips (retaining rings) for bores - Normal type and heavy type