3803184020 Sealing Ring For Homag Drilling Machine 3-803-18-4020

Product Description

Chasing a weeping or dust-ingesting spindle seat on a Homag boring line? This 3803184020 sealing ring — also written 3-803-18-4020 — is a drop-in metal seal for the Homag CNC vertical drilling spindle: 26 mm outer diameter, 22.5 mm inner diameter, 2 mm cross section, black finish. Those three figures are the whole fitment story, so you can check the ring with calipers before it ever goes near the machine, and reorder by number instead of by picture.

A Homag vertical drilling spindle fails at the seal in three familiar ways: chips and dust work into the seat, the spares drawer holds rings that all look alike, and a ring bought on "looks the same" arrives a fraction of a millimetre undersize, presses in loose, and weeps again in the same shift. This sealing ring is specified by dimension, so the third failure stops before it starts.

It is the metal sealing element for the Homag CNC vertical drilling spindle, listed as 3803184020 and 3-803-18-4020. Every fitment number is quoted openly: 26 mm outer diameter, 22.5 mm inner diameter and 2 mm thickness, written in one line as φ26 × φ22.5 × 2 mm. The gap between those two diameters leaves a 1.75 mm radial wall, the part that sits between bore and shaft.

Because both diameters are printed on the listing, the ring can be verified on the bench. Calipers across the 26 mm face, calipers inside the 22.5 mm bore, micrometer over the 2 mm section. If the three readings match the ring being replaced, the fit is the fit the spindle was built for.

The body is metal and the finish is black. One ring covers one spindle position, with no spacer and no adapter — the sealing element, the number, and the three dimensions you measured.

Product Features

Everything below comes from the part's own listing — dimensions, material and the spindle it is built for.

• 26 mm outer diameter — the figure that must match the housing bore; it is the first number in φ26 × φ22.5 × 2 mm and the first to check with calipers.
• 22.5 mm inner diameter — what centres the ring on the spindle side, quoted apart from the outer diameter so both interfaces can be measured, not guessed.
• 2 mm cross section — the thickness, listed as both thickness and cross section, so seat depth is checked against the same 2 mm figure.
• 1.75 mm radial wall — exactly half the difference between 26 mm and 22.5 mm; that wall is the sealing land, and the reason both diameters are quoted to 0.5 mm.
• Metal body, black finish — the ring is metal, so what you measure on the bench is what enters the bore: 26 mm, 22.5 mm, 2 mm, unchanged.
• Built for the Homag CNC vertical drilling spindle — the declared application is the sealing element of that spindle, not a general-purpose washer.
• Two part numbers, one ring — 3803184020 and 3-803-18-4020 resolve to the same sealing ring, so a parts list written either way matches.
• Single-piece supply — one ring per spindle position: no kit, no spacer, no adapter to count when you order.

Product Parameters

Product Advantages

Two things usually decide how long a spindle seat stays dry: whether the ring matches the bore, and whether the next one will match too.

• Replace the seat, not the spindle. A weeping 26 mm seat is a ring problem long before it is a bearing problem, and a ring is a fraction of the cost of pulling the spindle out of the line.
• Known dimensions before you pay. 26 mm, 22.5 mm, 2 mm and the calculated 1.75 mm wall are all visible up front, so the decision is made against a drawing, not a photograph.
• Reordering is a number, not a hunt. Quote 3803184020 or 3-803-18-4020 and the same sealing ring comes back; nobody has to match a picture from four years ago.
• Bench checks catch the wrong part early. Two caliper readings and one micrometer reading cover the whole fitment, so a mismatch is found at goods-in instead of mid-shift.
• Measured, not estimated. The two diameters differ by 3.5 mm, leaving the 1.75 mm wall, which is why a ring that is 'almost' the right size does not seal — the tolerance is the product here.
• One position, one ring. The sealing element is supplied as a single piece, so you replace the seat that is weeping instead of breaking open a full repair kit.

Frequently Asked Questions

Will this sealing ring fit my Homag CNC vertical drilling spindle?

Yes, if your parts list carries 3803184020 or 3-803-18-4020. Those are the two writing formats of the same metal sealing ring, and the declared application is the sealing element of the Homag CNC vertical drilling spindle. Check the old ring's 26 mm outer diameter before you commit.

What size is the 3803184020 sealing ring?

φ26 × φ22.5 × 2 mm — 26 mm outside, 22.5 mm inside, 2 mm thick. The same three figures are listed as outer diameter, inner diameter and thickness / cross section, and the wall between the two diameters works out at 1.75 mm.

Is 3803184020 the same part as 3-803-18-4020?

Yes, they are one ring. 3803184020 is the plain numeric SKU, 3-803-18-4020 is the dashed Homag-style model number, and both are used on this part's listing for the same metal sealing element.

What is the ring made of, and what colour is it?

Metal, with a black finish. No other material grade is declared for this part, so if a specification sheet asks for a compound or hardness value, treat that as a question for the supplier rather than a feature of the ring.

How do I check the size of the ring already in my spindle?

Measure three things: outer diameter, inner diameter and thickness. On a good ring those read 26 mm, 22.5 mm and 2 mm. Calipers across the face and inside the bore plus a micrometer over the section are enough — no disassembly drawing needed.

Can I replace only the sealing ring instead of the spindle?

Yes. The ring is supplied as a single piece at a single spindle position, so it is a replaceable element rather than part of a spindle assembly. Sealing elements wear at the seat; the housing and shaft do not have to come out with it.

How is the ring priced?

Price is quoted on enquiry, not published per piece. Send the part number 3803184020 (or 3-803-18-4020) with the quantity you need and the figure comes back against that number.

Which machine is this sealing ring listed for?

The Homag CNC vertical drilling spindle — that is the only application declared on this listing. It is catalogued under drilling machine parts, and its 26 mm outer diameter and 2 mm section belong to that spindle seat.