DIN 471 vs. DIN 472: Which Circlip Do You Need?

Every year, procurement teams in automotive, automation, and general machinery specify retaining rings by the million. In a gearbox, an electric motor, or a hydraulic cylinder, the right circlip is the difference between a bearing that stays seated and one that walks out under load. Two standards dominate the specification sheets: DIN 471 and DIN 472. They look similar in a catalogue, but they are not interchangeable — and ordering the wrong one can cost you a production stoppage, not just a return.

This guide walks you through the real difference between a DIN 471 external circlip and a DIN 472 internal circlip, shows you how to tell which one your assembly needs, and helps you avoid the ordering mistakes that slow projects down.

What DIN 471 and DIN 472 Actually Are

At the most basic level, the two standards describe where the ring sits:

A DIN 471 circlip is an external retaining ring. You fit it into a groove cut on the outside of a shaft, and it holds a component from sliding off the shaft end.
A DIN 472 circlip is an internal retaining ring. You fit it into a groove cut on the inside wall of a bore or housing, and it stops a component from moving inward or out of the bore.

Both are stamped from spring steel and hardened for fatigue resistance, but the groove geometry they match is a mirror image of each other. Get the standard wrong and the ring simply will not seat.

Figure 1: A DIN 471 external circlip (shaft retaining ring) seats in a circumferential groove on the shaft OD.

Installation Location — Shaft vs. Bore

The single decision that separates the two is the mounting location. The table below puts the two side by side so you can confirm the standard before you open the order form.

Attribute	DIN 471 (external)	DIN 472 (internal)
Standard	DIN 471	DIN 472
Mounting	On a shaft (outside groove)	In a bore (inside groove)
Also called	shaft circlip, external snap ring	bore circlip, internal snap ring
Groove location	Groove on shaft OD	Groove on bore ID
Size range	d = 3–300 mm	D = 8–300 mm
Typical use	Gears, bearings, pulleys on shafts	Bearing housings, sleeves, hydraulic bores

Figure 2: A DIN 472 internal circlip (bore retaining ring) seats in a circumferential groove on the bore ID.

If your component rides on a rotating shaft and needs to be retained axially outward, you need a DIN 471. If it sits inside a housing and must be held from drifting out of the bore, you need a DIN 472.

Applications Across Your Industry

The reason both standards stay in constant demand is that modern mechanical assemblies almost always need axial retention in two directions. Understanding that demand chain helps you forecast which ring your bill of materials actually calls for:

Automotive transmissions, reducers, and electric motors retain gears and bearings on output shafts — that is DIN 471 territory. Buyers in this segment specify external circlips in high volume and expect tight groove tolerances.
Bearing housings, hydraulic cylinders, and sleeves need a ring that holds the inner race or spacer inside the bore — that is DIN 472 territory.
General machinery and automation equipment use both, often in the same unit: a DIN 471 on the drive shaft and a DIN 472 in the housing bore.

EugeneTeco supplies both families to buyers across automotive, automation equipment, rail transit, and general machinery, with ready stock for standard sizes and custom production for drawings that fall outside the catalogue range. You can review the full range of standard circlips, washers and pins in our fastener catalogue.

How to Identify Whether Your Assembly Needs DIN 471 or DIN 472

Before you open the order form, answer one question: where is the groove?

Groove machined on a shaft shoulder → DIN 471 (external circlip).
Groove machined inside a housing or bore → DIN 472 (internal circlip).

Quick checklist:

Is the part you are retaining mounted on a shaft? → DIN 471.
Is it seated inside a tube, housing, or bore? → DIN 472.
Did your drawing call out an external (DIN 471) or internal (DIN 472) ring? → Match the standard, not the diameter.

When in doubt, send us the groove drawing — our engineering team confirms the standard and the size before you commit to an order. You can see the DIN 471 external circlip specifications to confirm dimensions and material options.

Selection Criteria Beyond Location

Once you know the standard, the size is driven by the groove, not just the shaft or bore diameter:

Groove diameter and width: these must match the circlip’s fitted dimensions. Ordering by shaft diameter alone is the most common error.
Material: 65Mn and C67S spring steel are the workhorses; stainless grades suit corrosive or wash-down environments.
Hardness: standard carbon-steel rings reach HRC 47–54 (up to 48 mm), with slightly lower hardness above that for larger sizes.
Surface: black phosphating is standard for wear and corrosion resistance; other finishes are available on request.

Still deciding on material or finish? List your working conditions — load, temperature, and corrosion exposure — and we will match the grade to your application before you order.

Common Ordering Mistakes to Avoid

Ordering by shaft or bore diameter only. The circlip size is set by the groove dimensions, not the nominal shaft size.
Mixing up external and internal. A DIN 471 will not seat in a bore groove, and a DIN 472 will not sit on a shaft — they are mirror-image parts.
Assuming an imperial ring is a drop-in substitute. Metric DIN sizes do not match inch-series rings; confirm the standard before substitution.
Choosing the wrong material for the environment. A plain carbon-steel ring in a damp or chemical environment loses retention strength prematurely.

For the internal side of your assembly, review the DIN 472 internal circlip product page to confirm dimensions and material options.

Specify with confidence

Download the DIN 471 and DIN 472 catalogues, confirm your groove dimensions, and send us your bill of materials. Our team returns a matched quote — usually within one working day.

Get the catalogues & a quote

Why Buyers Partner With EugeneTeco

Standards you can verify: IATF 16949 and ISO 9001 certified, with products conformed to DIN and ISO norms.
Proven material control: every batch goes through metallographic inspection to confirm stable mechanical properties — see how our metallographic inspection process works.
OEM & ODM flexibility: we custom-make special rings to your drawing and sample, with low trial-order support.
Ready stock and global shipment: standard sizes ship fast; packaging is standardized for safe international delivery.

Ready to order DIN 471 or DIN 472 circlips?

Send us your drawing or groove dimensions and get a quote tailored to your volume and material requirement.

Request a quote

Frequently Asked Questions

The questions below cover practical points that go beyond the standard-vs-standard comparison, so you can spec and order with fewer surprises.

What material grades are available for DIN 471 and DIN 472 circlips, and how do I choose?

Standard rings are stamped from 65Mn or C67S spring steel and hardened to around HRC 47–54. For damp, outdoor, or wash-down environments, stainless grades (such as SS420 or AISI 304/316) resist corrosion far better, though they trade off some hardness. Match the grade to your load and corrosion exposure rather than defaulting to carbon steel.

Are there ISO or ANSI equivalents to DIN 471 and DIN 472 that I can substitute?

DIN 471 and DIN 472 are German standards that are widely referenced worldwide, and comparable external/internal retaining rings exist under ISO and ANSI/ASME metric series. However, groove dimensions and thickness are not always identical across standards, so you should confirm the groove drawing before substituting one standard for another — do not assume a direct drop-in match.

How do I measure the groove to specify the correct circlip size?

Measure the groove diameter and groove width at the shaft or bore where the ring seats, then read the matching size from the standard’s dimension table. The circlip size follows the groove, not the nominal shaft or bore diameter — a 20 mm shaft can use different ring sizes depending on the machined groove. Always record both the groove diameter and width on your order.

Which surface treatment should I pick for a corrosive environment?

Black phosphating is the standard finish and gives good general wear and corrosion resistance for indoor machinery. For higher corrosion demands, ask about zinc plating, Dacromet, or stainless material instead of carbon steel with phosphate. The right choice depends on temperature, chemical exposure, and whether the ring is serviced regularly.

Can EugeneTeco supply non-standard or custom circlips, and what is the minimum order?

Yes. Beyond the catalogue range we manufacture custom rings to your drawing or sample under OEM/ODM, including special diameters, materials, and finishes. We support low trial orders so you can validate a new part before committing to volume — send your drawing and we will quote both prototype and production quantities.

What tools should I use to install and remove circlips without damaging the groove?

Use proper circlip pliers matched to the ring type — external pliers for DIN 471 and internal pliers for DIN 472. Fit the ring squarely into the groove and release it gently; never lever it in with a screwdriver, which can notch the groove or spring the ring. A deformed or over-stretched ring should be replaced, not reused.

Related Resources

Continue reading on the EugeneTeco knowledge base:

Written by the EugeneTeco engineering team. Specifications reflect DIN 471 / DIN 472 as commonly supplied; confirm groove dimensions against your drawing before ordering.

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