4-004-05-0012 LOCKING RING DIN 471 25X1 2 C67 Homag Woodworking Machinery Spare

When a shaft component on a Homag machine starts to drift or a bearing loses its shoulder, the cause is often a tired locking ring. A ring that has lost tension or worn thin allows end play, which shows up as vibration, noise, or poor cut finish.

The locking ring 4-004-05-0012 is a DIN 471 retaining ring with a 25 mm inner diameter and 1.2 mm thickness. It is formed from C67 high-carbon spring steel. This ring is used on Homag woodworking machinery. To confirm the fit, measure the shaft groove diameter and compare the existing ring's thickness to 1.2 mm, then cross-check the part number 4004050012 on the machine's parts list.

Mounting the ring requires compressing it into the shaft groove. Check that the groove is clean and free of burrs before fitting. The spring steel must seat fully in the groove, with the ring's ears accessible for removal. In use, correct seating keeps the ring from riding out under load, protecting adjacent components from lateral movement.

Supply is straightforward: the ring is packed as a single spare part unless customisation is agreed. No special packaging is stated. When enquiring, send the part number 4-004-05-0012 or 4004050012, the machine model, and the shaft groove dimensions. That lets the supplier confirm the 25X1,2 size against your application before dispatch.

What the specification fixes, and what it leaves to the machine:

• Shaft Retention — DIN 471 locking ring with 25 mm inner diameter fits into a machined shaft groove to hold components axially.
• Spring Steel Material — C67 high-carbon spring steel gives the ring the elasticity needed to snap into the groove and stay seated.
• Thickness Check — At 1.2 mm thick, the ring fits grooves machined for that thickness, so measure the old ring before ordering.
• Homag Fitment — This locking ring is intended for Homag woodworking machinery, matching the part number shown in the machine's parts list.
• Groove Seating — The ring must sit fully in the shaft groove; a partly seated ring can work loose under vibration.
• Ear Access — The ring ears allow removal with standard circlip pliers, so the ring can be changed without dismantling the shaft.
• Wear Point — Locking rings wear at the groove contact; a worn ring shows reduced tension and allows end play.
• DIN 471 Standard — Conforming to DIN 471 means the ring follows a recognised dimensional standard for external retaining rings.
• Part Number Match — Use 4-004-05-0012 or 4004050012 when ordering to avoid confusion with other 25 mm rings.

What changes on the shop floor when the right part goes back in:

• Restores shaft location. A fresh locking ring takes up end play that causes vibration and poor finish, returning the shaft to its intended axial position.
• Correct material for the groove. C67 spring steel is made to flex into the groove and hold tension, so the ring stays put through repeated machine cycles.
• Easy to replace. The ring can be removed and refitted with standard circlip pliers, cutting the time a machine stays down for a worn retaining ring.
• Standard sizing reduces guesswork. DIN 471 and the 25X1,2 size let you match the ring to a known groove, so you can order with confidence from the part number.
• Protects adjacent parts. By holding components in place, the ring prevents bearings and gears from rubbing against shoulders and wearing prematurely.
• Simple stock item. As a single spare part, it is easy to keep on the shelf and avoids waiting for a full assembly when only the ring has failed.
• Clear identification. The part number 4004050012 and 4-004-05-0012 make reordering straightforward and reduce the risk of fitting the wrong ring.
• It fits the machine you already run. The homag is made for woodworking machines, so it returns to the same shaft, bracket or spindle without re-machining the mounting.

Check the part number 4-004-05-0012 or 4004050012 against your machine's parts list and measure the shaft groove and old ring thickness.

It has a 25 mm inner diameter and 1.2 mm thickness, sized to DIN 471 for external retaining rings.

C67 high-carbon spring steel is used, which gives the ring the spring tension needed to stay in the shaft groove.

Reusing a ring is not recommended because spring tension drops after removal, so fit a new ring to keep components located.

Standard circlip pliers for external rings are used to compress the ring into the groove; check the groove is clean before fitting.

It is a DIN 471 external ring for a shaft groove, not an internal bore ring.

Send the part number 4-004-05-0012 or 4004050012, the machine model, and the shaft groove dimensions with your enquiry.

Measure the shaft groove diameter and the old ring thickness to confirm 25 mm and 1.2 mm, and match the part number.