Retaining Rings · DIN 471 / DIN 472

Grade 12.9 Steel Retaining Rings (Circlips)

Grade 12.9 Steel Retaining Rings (Circlips) pairs the standard DIN 471 / DIN 472 with a Grade 12.9 Steel base material. The sections below cover why engineers select this grade for retaining rings (circlips), its corrosion and temperature behavior, and the sizes available.

Why Choose Grade 12.9 Steel for Retaining Rings (Circlips)

The highest common strength class, for high-load machine assembly. For retaining rings (circlips), this matters when requires plating or black-oxide protection is the primary requirement.

Mechanical & Physical Properties

Grade designation	class 12.9
Magnetic response	Magnetic
Service temperature	up to approx. +300 °C
Corrosion characteristic	Requires plating or black-oxide protection

Galvanic & Galling Considerations

For retaining rings (circlips) in steel, the dominant compatibility issue is hydrogen embrittlement at high property classes (10.9 and above) when electroplated. Plating must be followed by an appropriate baking treatment, or a non-electroplated finish (mechanical zinc, zinc flake) should be substituted.

Comparable Grades

For Retaining Rings (Circlips), class 8.8 is the comparable strength step. Move up when the joint preload approaches the proof load of the current class; move down when the joint is over-specified. For corrosion-critical service, switch to stainless A2 or A4.

Sizes of Retaining Rings (Circlips) Available in Grade 12.9 Steel

Nominal diameter (mm)	Ring diameter d1 (mm)	Groove diameter d2 (mm)	Thickness s (mm)	Groove depth ref (mm)	Type / standard
3	2.7	2.5	0.4	3.5	DIN 471 external
4	3.7	3.4	0.4	4.5	DIN 471 external
5	4.7	4.4	0.6	5.5	DIN 471 external
6	5.6	5.3	0.7	6.5	DIN 471 external
7	6.5	6.2	0.8	7.5	DIN 471 external
8	7.4	7.1	0.8	8.5	DIN 471 external
9	8.4	8.1	1.0	9.5	DIN 471 external
10	9.3	9.0	1.0	10.5	DIN 471 external
11	10.2	9.9	1.0	11.5	DIN 471 external
12	11.1	10.8	1.0	12.5	DIN 471 external
14	13.0	12.7	1.0	14.5	DIN 471 external
15	14.0	13.7	1.0	15.5	DIN 471 external
16	15.0	14.7	1.0	16.5	DIN 471 external
17	16.0	15.7	1.0	17.5	DIN 471 external
18	17.0	16.7	1.2	18.5	DIN 471 external
19	18.0	17.7	1.2	19.5	DIN 471 external
20	19.0	18.7	1.2	20.5	DIN 471 external
22	21.0	20.7	1.2	22.5	DIN 471 external
24	22.9	22.6	1.2	24.5	DIN 471 external
25	23.9	23.6	1.2	25.5	DIN 471 external
28	26.9	26.6	1.5	29.0	DIN 471 external
30	28.9	28.6	1.5	31.0	DIN 471 external
32	30.9	30.6	1.5	33.0	DIN 471 external
35	33.8	33.5	1.5	36.0	DIN 471 external
40	38.5	38.2	1.75	41.0	DIN 471 external
45	43.5	43.2	1.75	46.0	DIN 471 external
50	48.5	48.2	2.0	51.0	DIN 471 external
55	53.3	53.0	2.0	56.5	DIN 471 external
60	58.3	58.0	2.0	61.5	DIN 471 external
65	63.3	63.0	2.5	67.0	DIN 471 external

Technical Drawing

Customize the parameters below — every spec field is editable, and the drawing redraws to match the values you choose. Changing the size will snap the other fields to that size's standard values; you can then override any individual value.

Sends the selected values to the quote form below.

Request a Quote

Adjust the parameters in the drawing above and click "Request this configuration" to send the exact specification straight to this form.

Category Type Standard Thread size Material Finish

Dimensions & Specifications (DIN 471 / DIN 472)

Nominal diameter (mm)	Ring diameter d1 (mm)	Groove diameter d2 (mm)	Thickness s (mm)	Groove depth ref (mm)	Type / standard
3	2.7	2.5	0.4	3.5	DIN 471 external
4	3.7	3.4	0.4	4.5	DIN 471 external
5	4.7	4.4	0.6	5.5	DIN 471 external
6	5.6	5.3	0.7	6.5	DIN 471 external
7	6.5	6.2	0.8	7.5	DIN 471 external
8	7.4	7.1	0.8	8.5	DIN 471 external
9	8.4	8.1	1.0	9.5	DIN 471 external
10	9.3	9.0	1.0	10.5	DIN 471 external
11	10.2	9.9	1.0	11.5	DIN 471 external
12	11.1	10.8	1.0	12.5	DIN 471 external
14	13.0	12.7	1.0	14.5	DIN 471 external
15	14.0	13.7	1.0	15.5	DIN 471 external
16	15.0	14.7	1.0	16.5	DIN 471 external
17	16.0	15.7	1.0	17.5	DIN 471 external
18	17.0	16.7	1.2	18.5	DIN 471 external
19	18.0	17.7	1.2	19.5	DIN 471 external
20	19.0	18.7	1.2	20.5	DIN 471 external
22	21.0	20.7	1.2	22.5	DIN 471 external
24	22.9	22.6	1.2	24.5	DIN 471 external
25	23.9	23.6	1.2	25.5	DIN 471 external
28	26.9	26.6	1.5	29.0	DIN 471 external
30	28.9	28.6	1.5	31.0	DIN 471 external
32	30.9	30.6	1.5	33.0	DIN 471 external
35	33.8	33.5	1.5	36.0	DIN 471 external
40	38.5	38.2	1.75	41.0	DIN 471 external
45	43.5	43.2	1.75	46.0	DIN 471 external
50	48.5	48.2	2.0	51.0	DIN 471 external
55	53.3	53.0	2.0	56.5	DIN 471 external
60	58.3	58.0	2.0	61.5	DIN 471 external
65	63.3	63.0	2.5	67.0	DIN 471 external
70	68.3	68.0	2.5	72.0	DIN 471 external
75	73.3	73.0	2.5	77.0	DIN 471 external
80	78.0	77.7	2.5	82.0	DIN 471 external
85	83.0	82.7	3.0	87.0	DIN 471 external
90	88.0	87.7	3.0	92.0	DIN 471 external
95	93.0	92.7	3.0	97.0	DIN 471 external
100	98.0	97.7	3.0	102.0	DIN 471 external
8	8.4	8.7	0.8	7.5	DIN 472 internal
9	9.4	9.7	1.0	8.5	DIN 472 internal
10	10.4	10.7	1.0	9.5	DIN 472 internal
11	11.4	11.7	1.0	10.4	DIN 472 internal
12	12.5	12.8	1.0	11.4	DIN 472 internal
13	13.5	13.8	1.0	12.4	DIN 472 internal
14	14.5	14.8	1.0	13.4	DIN 472 internal
15	15.5	15.8	1.0	14.3	DIN 472 internal
16	16.5	16.8	1.0	15.3	DIN 472 internal
17	17.5	17.8	1.0	16.3	DIN 472 internal
18	18.5	18.8	1.2	17.2	DIN 472 internal
19	19.5	19.8	1.2	18.2	DIN 472 internal
20	20.5	20.8	1.2	19.2	DIN 472 internal
22	22.5	22.9	1.2	21.2	DIN 472 internal
24	24.5	24.9	1.2	23.2	DIN 472 internal
25	25.5	25.9	1.2	24.2	DIN 472 internal
28	28.6	29.0	1.5	27.0	DIN 472 internal
30	30.6	31.0	1.5	29.0	DIN 472 internal
32	32.6	33.0	1.5	31.0	DIN 472 internal
35	35.7	36.1	1.5	34.0	DIN 472 internal
40	40.8	41.3	1.75	39.0	DIN 472 internal
45	45.8	46.3	1.75	44.0	DIN 472 internal
50	51.0	51.5	2.0	49.0	DIN 472 internal
55	56.0	56.5	2.0	54.0	DIN 472 internal
60	61.0	61.5	2.0	59.0	DIN 472 internal
65	66.2	66.8	2.5	64.0	DIN 472 internal
70	71.2	71.8	2.5	69.0	DIN 472 internal
75	76.2	76.8	2.5	74.0	DIN 472 internal
80	81.2	81.8	2.5	79.0	DIN 472 internal
85	86.5	87.1	3.0	84.0	DIN 472 internal
90	91.5	92.1	3.0	89.0	DIN 472 internal
95	96.5	97.1	3.0	94.0	DIN 472 internal
100	101.5	102.1	3.0	99.0	DIN 472 internal

Frequently Asked Questions

Are Grade 12.9 Steel Retaining Rings (Circlips) magnetic?

Grade 12.9 Steel Retaining Rings (Circlips) are magnetic.

What corrosion resistance do Grade 12.9 Steel Retaining Rings (Circlips) offer?

Grade 12.9 Steel Retaining Rings (Circlips) provide requires plating or black-oxide protection with a service range of up to approx. +300 °C.

When should I move from class 12.9 to class 8.8 for Retaining Rings (Circlips)?

Step up to class 8.8 when the joint preload approaches the proof load of the current class. The higher class adds preload at the same diameter, often saving size and weight.

Is Grade 12.9 Steel prone to hydrogen embrittlement?

Class 10.9 and above can be susceptible to hydrogen embrittlement when electroplated. Specify post-plating baking, or use mechanical-zinc / zinc-flake finishes which avoid the cathodic plating step.

How do I request a quotation?

Use the technical drawing on this page to pick the exact configuration, then submit it with the quote form. We respond within one business day.

Why Choose Grade 12.9 Steel for Retaining Rings (Circlips)

Mechanical & Physical Properties

Galvanic & Galling Considerations

Comparable Grades

Sizes of Retaining Rings (Circlips) Available in Grade 12.9 Steel

Technical Drawing

Request a Quote

Request a Quotation

Dimensions & Specifications (DIN 471 / DIN 472)

Frequently Asked Questions

Related Pages

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