How to Identify an Unknown Industrial Part

Every reseller, MRO storeroom and asset-recovery crew has the same pile: a bin of drives, sensors, contactors and motors pulled from a machine, and nobody wrote down what they are. Some have a clean nameplate. Some have a plate that has been through twenty years of coolant and grinding dust. Some have no plate at all, just an etched code on the housing.

Knowing how to identify industrial parts reliably is the difference between stock you can sell or reuse and stock that gets scrapped a second time. This guide gives a practical method for identifying an unknown industrial part, explains why parts lookup accuracy matters more than speed, and shows where AI-powered identification from a photo fits, especially for scrap, teardown and surplus intake.

A step-by-step method to identify an unknown industrial part

Work through the steps in order. Most parts are identified by step 2 or 3; the later steps exist for the hard cases.

1. Find and read the nameplate or rating plate

Nameplates are usually on the largest flat surface of the housing, on the terminal box cover of a motor, on the side of a drive, or on the top edge of a DIN-rail module. Clean the plate with a dry cloth, then photograph it straight on in good light. Raking light from the side often brings out stamped or etched characters that are invisible head-on.

On a readable plate, this single step usually gives you Brand, part number (MPN), type or designation code, serial number and the rating data (voltage, current, power, IP rating). If you use an AI nameplate scanner, this is where the photo goes: the app extracts those fields for you to review. More on that below.

2. Decode brand, type code, order number and serial

This is where most identification mistakes happen. A nameplate carries several numbers, and only one is the number you buy by.

Field on the plate	What it is	Use it for lookup?
Brand / manufacturer	Who made it	Yes, always pair with the MPN
Order number, article number, MLFB, part no.	The MPN: the catalog number the manufacturer sells	Yes, this is the primary key
Type / designation code	Human-readable model family and variant (e.g. 1LA7 096-4AA10, ACS355-03E-08A8-4)	Yes, often identical to or derived from the MPN
Serial number, S/N, FD, production code	Unique to that one unit	No, it identifies the unit, not the product
Firmware / hardware version	Revision of that unit	Only to check compatibility
Customer or asset tag	Whatever the previous owner stuck on it	No, remove or ignore

Two rules prevent most bad records: the MPN and the serial are never the same number, and an asset tag from the previous plant is not a part number. A QR code or DataMatrix on the plate usually encodes both, which is a quick way to confirm which is which (see step 4).

3. Use markings, connector, housing and dimensions when the plate is gone

When there is no plate, you are identifying by physical evidence. Collect these before you search:

Housing markings. Cast or laser-etched codes on the body, PCB silkscreen numbers, molded part numbers inside covers. Photograph every one; many are OEM part numbers for a sub-assembly.
Connector type and pinout. M12 A-coded versus D-coded, Harting frame size, terminal count, fieldbus type. This narrows a sensor or I/O module to a family quickly.
Mounting and frame. IEC frame size on a motor (shaft diameter and foot spacing), DIN-rail width on modules, flange pattern on a valve or pump.
Rating data on secondary labels. Coil voltage on a contactor, pressure range on a transducer, resolution on an encoder.
What it came off. The machine model and the position in it. A drive pulled from a specific packaging line usually appears in that machine’s spare parts list.

With a frame size, connector, voltage and a housing code you can usually reach a product family in the manufacturer’s selector, then narrow to a variant.

4. Read the barcode, QR or DataMatrix on the label

Many labels carry a 1D barcode (often the MPN or an EAN/UPC), a QR code, or a DataMatrix cell that encodes several fields at once. Scanning it is faster than typing and removes the “was that a 0 or an O” problem entirely.

A QR and barcode reader built into the same app as the nameplate scanner lets you decode the code and read the plate text in one pass, then compare them. If the barcode says one MPN and the printed text says another, the printed text is usually a type code and the barcode is the order number; record both.

5. Verify against manufacturer catalogs and cross-references

A number is a hypothesis until you check it. Paste the MPN into the manufacturer’s product finder (Siemens Industry Mall, ABB Library, Schneider, SICK and ifm all have one). Confirm three things:

The product page exists and the brand matches.
The rating data on the page matches your plate or your measurements.
The product photo looks like the part in your hand: same housing, connector and terminal layout.

If any of the three fails, you probably have a close variant. Go back to the type code and check the suffix characters one by one; a single letter often changes the voltage, the output type or the mounting.

6. Check for equivalents, successors and obsolescence

Once the MPN is confirmed, note whether the product is active, phased out or discontinued; most manufacturers list a successor on the product page. For resale this matters twice over: discontinued parts with no direct successor are often the most valuable items in a teardown lot, and active parts with a cheaper successor are the hardest to price.

Parts lookup accuracy: why one wrong character finds the wrong part

Industrial part numbers are unforgiving. A Siemens motor MLFB such as 1LA7 096-4AA10 and 1LA7 096-4AA11 differ by one final digit and are different products. An ABB drive code where -4 becomes -2 is a different voltage class. A sensor with PNP versus NPN in the suffix will not work in the same circuit. A lookup process that gets the MPN “mostly right” is a process that files, quotes and ships the wrong part, and the error only surfaces when a customer calls.

Three habits keep parts lookup accuracy high:

Confusable characters. 0/O, 1/I/l, 5/S, 8/B, 2/Z. Manufacturers rarely mix letters and digits randomly, so if a position in the code is a digit everywhere else in that family, read it as a digit. When in doubt, check the barcode.
Review before save. Whoever captures the record should see the photo and the extracted fields side by side and confirm them before the row is written. This is the highest-leverage step, whether you are typing or using OCR. The post on nameplate OCR accuracy tips covers lighting, angle and cleaning.
Serialized MPN matching. Store the MPN and the serial as separate fields, never concatenated. A serial in the MPN field breaks every marketplace and catalog search, and makes two identical products look like two SKUs.

AI-powered identification from a photo, including scrap and teardown

Everything above can be done by hand. The bottleneck is that a careful human takes several minutes per part to read, decode, type and check, and a teardown lot might contain three hundred parts. AI-powered scrap identification shortens the first half of that work. With AutomaSnap, which runs in the phone browser, the workflow for a part pulled from a decommissioned machine looks like this:

Photograph the nameplate. The app extracts Brand, MPN, Designation code, Serial number and the specs it can read (voltage, power, IP rating) as editable fields. On a readable plate, Brand and MPN are usually right on the first pass; on a worn one, the fields come back partially filled and you complete them while you still have the part in your hand.
Review and correct. The photo and the fields sit side by side. This is the review-before-save step from the previous section, built into the flow.
Enrich the record. Optional Data Enrichment adds EAN/UPC where one exists, a product category, and an SEO title and description, so the row is listing-ready rather than just a code.
Check the market. Quick Market Check opens eBay and Automa.Net searches for that MPN with one tap, which tells you in seconds whether the part is worth cleaning and listing or goes to the recycler.
Clean the product photo. Background Remover turns a photo taken on the workshop floor into a listing image.
Export or publish. CSV or XLSX for your ERP or spreadsheet, direct export to WooCommerce, PrestaShop, Odoo, BaseLinker or Shopify, or publish the listing to eBay.

For an asset-recovery or scrap team, the practical change is that the person doing the teardown creates the record at the machine, instead of someone re-identifying everything from a box a week later. See parts identification from photo for the full flow.

Two honest limits. The app reads what is on the label and the housing; it does not read drawings or PDFs, and it does not guarantee a match. Catalog verification (step 5) is still your job, which is why the fields are editable. For the underlying technique, see how AI identifies products from photos.

Gal-Industry, a spare-parts reseller, moved its intake to this workflow and cut per-item handling from over ten minutes to seconds, roughly 15x faster from part in hand to listing. The Gal-Industry case study has the details.

A short worked example: a motor, a drive and a sensor

Three parts from one decommissioned filling line.

The motor. Plate intact but oily. Wipe, photograph, extract. Fields come back with Brand, the MLFB order number, the type designation, the serial, 2.2 kW, 400 V, IP55. Step 5 confirms the product page and the rating. Quick Market Check shows active listings, so it is cleaned, photographed and exported to eBay the same afternoon. About two minutes.

The drive. Plate readable, but the order number ends in a character that could be 1 or I. The DataMatrix on the side of the housing decodes cleanly and settles it: digit 1. The manufacturer page shows the model is phased out with a named successor, which goes into the description because buyers of discontinued drives search for exactly that.

The sensor. No plate. The label has peeled, leaving a molded housing code, an M12 4-pin connector and “PNP NO” printed on the cable. The extraction from the housing code gives a Brand and a partial MPN. The manufacturer’s selector, filtered by family, connector and output, leaves two candidates that differ by sensing range, and the range is printed on the lens ring. Identified, but it took ten minutes and a human at every step. That is normal for unplated parts, and still worth it: a matched sensor sells, an unmatched one does not.

Checklist: before you save the record

Brand and MPN in separate fields, MPN exactly as the manufacturer prints it
Serial number in its own field, not in the MPN
Barcode, QR or DataMatrix decoded and compared with the printed text
Rating data (voltage, power, range, IP) recorded from the plate
Product page found; photo, brand and rating confirmed
Lifecycle status noted: active, phased out, or discontinued with successor
Source machine and position noted for teardown lots

FAQs

What is the fastest way to identify an industrial part with no nameplate?

Photograph every marking on the housing, the connector and any secondary labels, then measure the mounting (shaft diameter and foot spacing for a motor, DIN width for a module, flange pattern for a valve). Combine the housing code with the connector type and rating data in the manufacturer’s product selector to reach a product family, then narrow to a variant. If you know which machine the part came from, that machine’s spare parts list is often the quickest route.

What is the difference between a part number and a serial number on a nameplate?

The part number (also called order number, article number, MLFB or MPN) identifies the product the manufacturer sells, and it is the number you search catalogs and marketplaces with. The serial number identifies one specific unit and changes from unit to unit. Record both in separate fields, and never search by the serial.

How accurate is AI nameplate identification on worn or scrap parts?

On a clean, readable plate, Brand and MPN are usually correct on the first pass. On faded, scratched or partially missing plates, the extraction typically returns some fields filled and some blank or uncertain, which is why the fields are editable and a review step comes before saving. Treat the extracted MPN as a strong first draft and confirm it against the manufacturer’s product page, especially the final characters of the code.

Can I check whether a scrapped part is worth listing before I catalog it?

Yes. Once the MPN is captured, a Quick Market Check opens eBay and Automa.Net searches for that number so you can see current listings and asking prices in seconds. That lets a teardown crew decide at the machine whether a part is worth cleaning and photographing or should go straight to the recycler.