What a bolt-on base is doing on a loader lip
On a new WA380 bucket the tooth socket usually seats on a nose cast into the lip, and no base is involved. That nose does not last forever. It wears, it gets built up with weld, and eventually it is cut off and replaced with a separate plate — a base — because rebuilding a cast nose on the machine is not a job anyone wants twice. Once that plate is on, every tooth order has to match the plate, not the machine model.
423-847-1111 is that plate for the centre position in this class: three holes, bolted to the lip, with the monoblock tooth bolting through it. It is the part that decides whether the next set of teeth fits, and it is the part nobody photographs when they ask for a price.
Bolt-on or weld-on — the decision is the lip, not the price
| Base | Type | Printed weight | Coverage as printed |
|---|---|---|---|
| 423-847-1111 | Bolt-on, three holes, centre | 15.0 kg (two tables); 13 kg in one spec block | 538, 542, 545, WA350, WA380, WA380Z, WA400, WA420, WA430, WA450, WA470, WA480 |
| 423-847-1211 | Two-strap weld-on | 12.80 kg | WA380-38 and up, listed across WA380 / 400 / 420 / 450 / 470 |
A bolt-on base is a field replacement — unbolt, bolt on, torque. A weld-on base is welded to the lip: the lip has to be sound enough to take the weld, the position is set by the welder rather than by a hole pattern, and from then on the base is part of the bucket. Both are legitimate; they are answers to different conditions. If a lip has already been rebuilt once, welding again is usually the wrong answer, and if the lip is original and thin, bolting a base onto it is not much better.
Weight: why 15.0 kg is a catalogue figure
Two catalogue tables print 15.0 kg for 423-847-1111. One supplier's spec block prints 13 kg for the same number — a 2 kg difference on a part this size is either a different casting or a typo, and we cannot tell which from the page. We weigh each lot and put the weighed figure on the packing list. On a forty-piece order the difference between 13 and 15 kg a piece is 80 kg, which is a different freight bracket, so it is worth asking for the weighed figure before booking air freight rather than after.
Fitting it, and what fails next
Three points decide whether the set lasts:
- The lip under the base. A base bolted to a dished or cracked lip will move, and a moving base loads the bolts in shear instead of clamping the tooth. Check the lip flat with a straight edge before fitting.
- Bolt preload. The bolts hold the tooth by clamping, not by filling the holes. Reused bolts that have stretched will not hold the same preload; on a loader in rock, reusing them is how a corner tooth ends up in the tyre channel.
- The socket, not the tip. A monoblock tooth wears out at the socket before the point is gone. When the socket opens, the tooth walks and the bolts loosen — replacing the tooth is the fix, not tightening it again.
FAQ
Q: What is 423-847-1111?
A: A three-hole bolt-on base for the centre position of a WA380-class bucket, used where the lip carries a replaceable base instead of a cast nose. Published at 15.0 kg; it takes the centre tooth 423-70-13114.
Q: 423-847-1111 or 423-847-1211?
A: Bolt-on versus two-strap weld-on. The bolt-on comes off in the field; the weld-on becomes part of the lip and is a workshop job. Decide on the condition of the lip, not on the price of the base.
Q: How much does it weigh?
A: Two tables print 15.0 kg, one spec block prints 13 kg for the same number. We weigh each lot and quote freight on the weighed weight.
Q: How do I know if my bucket needs a base at all?
A: Look at the lip edge. Cast nose — the tooth bolts straight on, no base. Separate plate bolted or welded to the lip — that plate is the base and its number has to match. Send a side photo before ordering.
Sources
Part number, base type, published weight, machine coverage and the weld-on alternative on this page come from BDI Wear Parts' Komatsu bucket teeth and adapter list and SJ-GET's Komatsu loader adapter pages, read in October 2026, with the tooth and fastener numbers taken from the same catalogues' 423-70-13114 rows. Komatsu and the part numbers referenced are the property of their respective owners and are used here for fitment reference only. No Komatsu genuine catalogue page for this number is in our hands, so nothing here is presented as genuine-parts data, and no price is published — these are quotation items.