Scope of application

DIN 471 and DIN 472 circlips are used for axial protection of machine components on shafts and in bores.

The standards specify the geometric dimensions, groove widths, mounting diameters and elastic parameters of the rings.

DIN 471 applies to shaft rings (external).
DIN 472 applies to rings for holes (internal).

Dimensional markings according to DIN

DIN 471 and DIN 472 use the following geometric designations:

d1 – nominal diameter of shaft (DIN 471) or bore (DIN 472)
s – thickness of ring
m – width of mounting groove
t – depth of groove
d3 – diameter of ring in free state
n – height of ring protrusion above surface
d4 – diameter of outer ring circle

The parameters of the groove must be made in accordance with the standard, as they directly affect the axial load carrying capacity and durability of the connection.

DIN 471 – shaft circlips

The ring is mounted in a groove made on the shaft and protects the component from axial displacement.

Installation requirements

The groove should be made in accordance with the standard dimensions.
The edges of the groove must be chamfered.
The surface of the shaft should be free of burrs.
Perform the installation with the use of pliers for circlips.

Table of basic dimensions – DIN 471

DIN 471 – shaft circlips

DIN 471 – shaft circlips (range 10-200 mm)

Shaft diameter d [mm]	Ring thickness s [mm]	Groove width m [mm]	Groove depth t [mm]
10	1,0	1,1	0,6
15	1,0	1,1	0,8
20	1,2	1,3	0,9
25	1,2	1,3	1,1
30	1,5	1,6	1,1
35	1,5	1,6	1,3
40	1,75	1,85	1,3
50	2,0	2,1	1,6
60	2,0	2,1	1,8
80	2,5	2,6	2,0
100	3,0	3,1	2,4
120	3,0	3,1	2,8
150	3,5	3,6	3,5
180	4,0	4,1	4,0
200	4,0	4,1	4,5

DIN 472 – bore circlips

The ring is installed in a groove made in the hole and protects the component from axial displacement.

Installation requirements

The groove in the hole should be made concentric.
Ensure proper groove depth and width.
Carry out the assembly with appropriate assembly pliers.

Table of basic dimensions – DIN 472

DIN 472 – bore circlips

DIN 472 – circlips for holes (range 10-200 mm)

Bore diameter D [mm]	Ring thickness s [mm]	Groove width m [mm]	Groove depth t [mm]
10	1,0	1,1	0,6
15	1,0	1,1	0,8
20	1,2	1,3	1,0
30	1,5	1,6	1,2
40	1,75	1,85	1,4
50	2,0	2,1	1,7
60	2,0	2,1	1,9
80	2,5	2,6	2,1
100	3,0	3,1	2,5
120	3,0	3,1	2,9
150	3,5	3,6	3,6
180	4,0	4,1	4,2
200	4,0	4,1	4,6

Effect of groove design on component strength

Making a groove for a circlip causes a local reduction in the active cross-section of the shaft or body, which leads to an increase in stress concentration in this area.

For axial and dynamic loads, consider:

– weakening of the section at the groove,
– possibility of micro-cracks in case of fatigue,
– influence of centrifugal forces at high rotational speeds.

In the case of shafts operating at high speeds, the outer rings (DIN 471) may lose some of their clamping force under the influence of centrifugal force. Under such conditions, additional analysis of axial load carrying capacity and structural protection is recommended.

The selection of the ring should take into account not only the nominal diameter, but also the actual axial loads and the nature of the operation of the assembly.

Types of design of circlips

Depending on the method of manufacture and design purpose, circlips are divided into:

Stamped rings
Made from spring steel by punching and heat treatment. They are characterized by good elasticity and uniform pressure in the groove. Most commonly used in standard industrial applications.

Wire rings
Made of round, square or rectangular wire. Characterized by higher elasticity and lower stress concentration in the groove. Used in smaller diameter applications.

Turned Rings
Made by machining. Designed for applications with increased strength requirements. Allow installation in both directions due to symmetrical edge geometry.

The selection of the type of ring should take into account the nature of the axial load, rotational speed and the design requirements of the assembly.

High-speed operation

In the case of shaft-mounted rings (DIN 471), it is necessary to take into account the effect of centrifugal force acting during high-speed operation.

Centrifugal force reduces the pressure of the ring against the bottom of the groove, which can lead to:

– reduction in axial load carrying capacity,
– loss of positioning stability,
– slipping of the ring out of the groove under overload conditions.

When designing assemblies that operate at high speeds, it is important to:

– verify the permissible operating speed,
– check axial loads,
– take into account the design safety factor,
– apply additional axial protection if necessary.

In applications with very high speeds, design analysis is recommended in accordance with the manufacturer’s documentation and applicable technical standards.

Technical notes

Grooves should be made according to DIN dimensions.
Sharp edges and burrs are unacceptable.
Check the depth of the groove to ensure proper seating of the ring.
In the case of heavy axial loads, the load capacity of the ring should be checked.