20 mm Internal Retaining Ring (Bore Circlip), DIN 472

The 20 mm internal retaining ring (DIN 472) fits a 20 mm bore with a groove diameter of 21 mm, and is 1 mm thick. Here as simplified STEP files.

How these parts are made, and what the levels mean: read the method

• Also searched as: 20 mm circlip
• Model id: din472-d20
• Standard: DIN 472:2017 · size 20 mm

Files

Part key	Simplified
din472-d20	STEP

Dimensions

Symbol	Name	min	nom	max	Modeled	Rule	Level
s	Ring thickness		1		1	nominal	L1
s_lim	Ring thickness, limits	0.94		1	0.97	midpoint of min–max	L0 (max: one source)
d3	Free diameter		21.5		21.5	nominal	L1
d3_lim	Free diameter, limits	21.37		21.92	21.645	midpoint of min–max	L1
a	Lug height			4.2	4.2	single limit (max), modeled at the limit	L1
b	Radial width		2.3 ref		2.3	reference value	L1
d5	Plier hole diameter	2			2	single limit (min), modeled at the limit	L1
d2	Groove diameter		21		21	nominal	L1
m	Groove width		1.1		1.1	nominal	L1
n	Groove edge margin	1.5			1.5	single limit (min), modeled at the limit	L1

Drawing

As a PDF: CC-DIN472-SZ-20.pdf.

The 20 mm internal retaining ring beside the 19 mm and the 21 mm

The 20 mm is number 13, counting from the smallest, of the 17 DIN 472 internal retaining rings published here, from 8 mm to 25 mm.

• Ring thickness (s): 1 mm on the 20 mm internal retaining ring, the same on the 19 mm and the 21 mm.
• Ring thickness, limits (s_lim): 0.94 to 1 mm on the 20 mm internal retaining ring, the same on the 19 mm and the 21 mm.
• Free diameter (d3): 21.5 mm on the 20 mm internal retaining ring, against 20.5 mm on the 19 mm and 22.5 mm on the 21 mm.
• Free diameter, limits (d3_lim): 21.37 to 21.92 mm on the 20 mm internal retaining ring, against 20.37 to 20.92 mm on the 19 mm and 22.37 to 22.92 mm on the 21 mm.
• Lug height (a): up to 4.2 mm on the 20 mm internal retaining ring, against up to 4.1 mm on the 19 mm and up to 4.2 mm on the 21 mm.
• Radial width (b): 2.3 mm (reference) on the 20 mm internal retaining ring, against 2.2 mm (reference) on the 19 mm and 2.4 mm (reference) on the 21 mm.
• Plier hole diameter (d5): at least 2 mm on the 20 mm internal retaining ring, the same on the 19 mm and the 21 mm.
• Groove diameter (d2): 21 mm on the 20 mm internal retaining ring, against 20 mm on the 19 mm and 22 mm on the 21 mm.

Other sizes

• One size smaller: 19 mm Internal Retaining Ring (Bore Circlip), DIN 472, 19 mm bore, 20 mm groove, 1 mm thick.
• One size larger: 21 mm Internal Retaining Ring (Bore Circlip), DIN 472, 21 mm bore, 22 mm groove, 1 mm thick.

Documents

• CC-DIN472-DS-20.pdf: 20 datasheet: values with levels, sources
• CC-DIN472-SZ-20.pdf: 20 drawing: this size's values on the views
• parts.json: the part record of this size (the platform contract)

Sources

fasten-it-din472, fasteners-eu-din472, hc-maschinentechnik-din472, seeger-din472. Full citations: the method page and this size's datasheet.

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