A circlip sits in a groove and takes a thrust load on its face: the groove diameter, groove width and ring thickness are what the standard fixes, per shaft or bore size. Stock covers the DIN sizes in spring steel and most of them in stainless. A shaft that was grooved to an inch ring, a groove worn wider, a ring that must be thicker for the load or made of a material the catalogue skips is a ring that gets made.
EKINSUN LTD is a custom parts manufacturer that makes retaining rings to drawing: a ring for an inch or worn groove, a thicker ring for a higher thrust, a ring in 316L, beryllium copper or PEEK, a lugged or tabbed ring of your own shape, a stop ring above the stock sizes. The stock table below is read from a 2026 catalogue; the groove table explains what the numbers mean; the negative-space table marks the border between buying and making.
"The shaft is 1 1/4 inch with a groove for an SAE ring. The nearest DIN 471 is 32 mm and it sits loose in the groove."
Inch grooves on metric shafts, and metric rings in inch grooves, are the commonest retaining-ring enquiry we see.
| Type | Standard | Fits | Stock range | Stock materials |
|---|---|---|---|---|
| External circlip (shaft ring) | DIN 471 / ISO 8752-type lugs | groove on a shaft | 4–150 mm stainless; 6–300 mm spring steel; 3–140 mm zinc steel | 304 / 1.4122; 65Mn phosphated, zinc |
| Internal circlip (bore ring) | DIN 472 | groove in a bore | 8–150 mm stainless; 4–220 mm spring steel; 9–150 mm zinc steel | 304 / 1.4122; 65Mn |
| E-clip (radial ring) | DIN 6799 | groove on a small shaft, fitted from the side | 1.2–15 mm | 304; zinc steel |
| Round-wire snap ring, external | DIN 7993 A | shallow groove on a shaft | 4–140 mm | spring steel |
| Round-wire snap ring, internal | DIN 7993 B | shallow groove in a bore | on request | spring steel |
| Lugged rings, heavy-duty | DIN 983 (external) / DIN 984 (internal) with lugs | as circlips, higher thrust | on request | spring steel |
| Push-on (starlock) washer | maker series | plain shaft, no groove | M3–M12 | black spring steel |
| Wire spring clips | maker series | hose and tube | M5–M14 | yellow-zinc spring steel |
| Stop ring (large) | maker series | large shafts | 30–250 mm | 50Mn spring steel |
| Bearing lock washer, multi-tab | DIN 5406 | KM lock nuts | M10–M60 | black steel — see bearing lock nuts |
| Number | Where it comes from | Why it matters |
|---|---|---|
| Shaft or bore diameter d | the part | picks the ring size in the standard |
| Groove diameter | DIN 471 / 472 table for that d | the ring must seat at its free diameter; a wrong groove lets it climb out under thrust |
| Groove width | DIN table; ring thickness plus clearance | too narrow and the ring will not seat; too wide and the ring tilts and the assembly rattles |
| Ring thickness s | DIN table | sets the thrust capacity together with the groove depth and the shaft material |
| Free diameter and lug holes | DIN table | the pliers must open the ring past the shaft without overstressing it |
| Edge margin | distance from groove to shaft end | a groove too close to the end shears the shaft shoulder before the ring fails |
Two things are worth measuring before any ring is ordered: the groove diameter with a caliper on the groove bottom, and the groove width with a feeler. A groove cut to an inch or a maker’s own table will not take a DIN ring, and a worn groove needs a thicker ring or a re-cut groove.
| What you need | In the catalogue? | What we make |
|---|---|---|
| DIN 471 or DIN 472 circlip in a DIN size, spring steel or 304 | Yes | Buy it from stock. No one-off competes with a stamped circlip. |
| E-clip DIN 6799 1.2–15 mm, wire ring DIN 7993 4–140 mm, starlock M3–M12 | Yes | Stocked; buy it. |
| A ring for an inch groove (SAE / ASME B27.7 sizes) on a metric shaft, or a metric ring in an inch groove | No | Stamped or wire-cut to the groove you measure, from 1 piece. |
| A thicker ring for a worn groove or a higher thrust, in a DIN diameter | No | Cut from thicker spring stock; groove re-cut if the drawing allows. |
| A circlip in 316L, beryllium copper, Inconel or PEEK | No | Wire-cut or machined in the material named. |
| A ring of your own shape — extra lugs, a tab, a flat, a keyed ring | No | Stamped or wire-cut to drawing — see custom stamped parts. |
| A stop ring or internal ring above the stock sizes | No | Machined or wire-cut from spring steel plate. |
| A retaining ring in aluminium 6061 or 7075 | No | Not offered: aluminium has no spring; we quote a machined collar or a stainless ring instead and say why. |
| Material | Designation | Where it fits here |
|---|---|---|
| Spring steel | 65Mn, C67S, C75S; phosphated and oiled, zinc, black | stock circlips, E-clips, wire rings |
| Stainless spring steel | 1.4122 / 1.4310; 304 / 1.4301 | stock stainless circlips 4–150 mm |
| Stainless 316L | 1.4404 / A4 | wire-cut rings for chemical service |
| Beryllium copper | CuBe2 | non-magnetic, non-sparking rings to order |
| PEEK | PEEK | insulating rings to order |
| Alloy steel | 42CrMo4 / 1.7225 | machined collars where a ring will not do |
| Aluminium 6061 | AlMg1SiCu | the shaft or housing; not a ring material |
| Aluminium 7075 | AlZn5.5MgCu | as above |
DIN 471 rings are external: they sit in a groove on a shaft and are opened with pliers to fit. DIN 472 rings are internal: they sit in a groove in a bore and are compressed to fit. Both are sized by the shaft or bore diameter, with the groove dimensions given in the standard.
From the groove, not the shaft. Measure the groove diameter at the bottom and the groove width; look those up in the DIN 471 or 472 table to find the ring, and check the ring thickness fits the width. A groove that matches no DIN row was cut for an inch or a maker's ring.
Rings that were opened only as far as the pliers needed usually can, but a ring that has been over-spread stays enlarged and will not seat. Rings in critical or high-speed assemblies are replaced with the part.
Yes. Rings are stamped or wire-cut to the groove you measure, in spring steel, stainless, beryllium copper or PEEK, thicker where the groove is worn, from 1 piece.
EKINSUN LTD is a custom parts manufacturer that makes circlips, E-clips, wire rings and special retaining rings to drawing in spring steel, 304 / 316L stainless, beryllium copper and PEEK, from 1 piece, with a quote within 12 hours.
No list price. The drivers are the process (wire-cut for a few pieces, a stamping die for thousands), the material and the size. A handful of stainless rings for an inch groove are wire-cut and priced by the piece; a production run is priced by the die plus press time. The quote states which.
Shaft or bore diameter, groove diameter, groove width, thrust load, material, quantity. A photo of the groove with a caliper is enough. From 1 piece, quote within 12 hours.
Retaining rings stamped or wire-cut to your groove, thickness and material — from 1 piece, quote in 12 hours.