Identify the machine and the marked number separately, find the orderable part in the matching catalog, and check any supersession before requesting a quotation. A readable number identifies a candidate; it does not by itself prove authenticity, current ordering status or fitment for your machine.
1. Collect the machine and component evidence
Start with a photograph of the machine plate and transcribe the full model suffix and serial number exactly, including leading zeros. Keep the engine serial in a separate field. Photograph the component in context and each readable label or marking without entering an unsafe area or dismantling an unsupported assembly.
| Check | Evidence and decision |
|---|---|
| Machine record | Full model, serial, engine identity where relevant, market/configuration and plate photograph. |
| Component record | Every visible number, label and installation position. Mark uncertain characters as unknown rather than guessing. |
| Photo set | Overall part, close label, mounting and external interfaces. Include a scale only when measurements can be obtained safely. |
Copying text from a photo can save time, but verify every character against the original. A slash joining two seller numbers is not proof that either is the correct ordering number.
2. Decide what the number actually represents
| Check | Evidence and decision |
|---|---|
| Marked number | A character string observed on a part. Its meaning still needs to be established. |
| Casting number | May identify a casting rather than the complete saleable assembly; retain it as an observation until the catalog resolves it. |
| Assembly number | Identify which items are included. A complete assembly and an internal service part are not interchangeable order scopes. |
| Packaging label | Useful identity evidence when linked to the actual supplied item; it does not establish the machine’s serial applicability. |
Do not discard the original photo when a catalog match is found. Keep both the observed marking and the confirmed order number so a later discrepancy can be traced.
3. Match the catalog, then check the number relationship
- Select the machine documentation using the full model and serial.
- Locate the assembly and illustrated position, not just a similar product name.
- Record the publication/version, figure and item number.
- Check whether a current manufacturer record links the old number to a successor.
- Retain any serial, configuration or companion-part conditions.
“A supersedes B” means A is the newer number replacing B in the cited record. “B is superseded by A” describes the same direction. A cross-reference merely links numbers; it does not automatically establish interchangeability. If the direction or scope is unclear, hold the ordering decision.
Komatsu’s parts portal describes access to parts and machine-specific manuals through My Komatsu. Use the actual applicable catalog record as the evidence for a particular match.
4. Worked example from the current catalog: 04120-21760
Komatsu’s official exact-number page identifies 04120-21760 as a V-Belt. That supports the number-to-product-name relationship. The Danch listing associates it with PC400-7, but that association remains pending serial and installation verification.
Manufacturer reference: 04120-21760 V-Belt
| Check | Evidence and decision |
|---|---|
| Established here | The manufacturer page identifies the exact number as a V-Belt. |
| Still required | The customer’s full machine serial, installed belt position and applicable catalog match. |
| Correct decision | Proceed with an identification inquiry; do not claim confirmed PC400-7 fitment from this example alone. |
04120-21760 V-Belt for Komatsu PC400-7 — View the registered product and its application boundary.
Machine context: PC400-7 parts guide.
5. Send an identification packet, not an unsupported conclusion
Use one line per required item. Include the observed number, proposed order number, quantity, plate photo, component photos and catalog reference. Where the number is unresolved, say so explicitly. The supplier can then identify the missing evidence rather than treating a guess as a confirmed specification.
| Check | Evidence and decision |
|---|---|
| Ready for identification | Machine and part evidence are provided, but the catalog or successor relationship is unresolved. |
| Ready for fitment review | The proposed orderable number and supporting record are available. |
| Hold | Numbers disagree, markings are unreadable, or an assembly scope remains unclear. |
An identification result should record who checked it, the date and the source. An editorial article cannot supply that customer-specific sign-off.
Frequently asked questions
Can I use only the number stamped on the housing?
Record it, but establish whether it is a casting mark or an orderable assembly number using the matching catalog.
Does a successor number fit every application of the old number?
Do not assume that. Preserve the direction, serial scope and any companion-part conditions in the cited record.
What if a character is unreadable?
Send the original close-up and mark the uncertainty; do not silently substitute a likely digit.
Is the belt example a confirmed PC400-7 fitment?
No. The exact product identity has a manufacturer reference, while the registered application still needs serial and installation checks.
Continue the ordering process
Editorial basis and evidence boundaries
Published by Danch Machinery. Editorial update: 14 September 2026. The workflow follows the company’s approved parts terminology and verification policy; the linked manufacturer and ICC pages support only the stated points. Live catalog examples were checked against the current Danch records. No customer case, stock position or technician signature is invented.
A customer-specific fitment approval requires its own evidence, responsible checker and date. This guide is not a repair procedure, an authenticity certificate or an authorization claim. Existing product photos are retained with their stated evidence limits.
Prepare your parts inquiry
Send the complete machine identity, exact part number or clearly marked uncertainty, quantity and supporting photographs.
About this guide
Published by Danch Machinery as general parts-identification and service-planning information. It is not a signed technical inspection or a machine-specific repair approval. Refer to the sources and scope stated in the article; confirm service procedures and fitment with the current manufacturer documentation for the exact machine.
Machine configurations and service requirements can differ by model, serial number and market. Confirm procedures and fitment with the current manufacturer documentation for your exact machine.
