Find the size designation and the manufacturer's part number, then match them with the belt profile and engine application. Start with the PK example below for serpentine belts.
Serpentine belt markings
A belt part number is the manufacturer's ordering reference; a PK size code describes rib count, profile and effective length. Photograph both before searching for a replacement.
Six longitudinal ribs.
Automotive V-ribbed belt profile.
1,003 mm effective length, not an outside-circumference measurement.
This is a marking example, not a vehicle fitment recommendation. Do not apply the PK format to a timing-belt code or a manufacturer's unrelated part-number system.
Gates technical bulletin: reading PK numbersEvidence before interpretation
Photograph the belt and package before cleaning, straightening or discarding them. Copy the marking exactly, including spaces, prefixes and suffixes, and leave damaged characters unresolved.
Record whether the belt came from an accessory drive, a synchronous timing drive or another known application. If the role is uncertain, keep it open.
Add make, model, model year, engine code or displacement, destination market and the belt location or service job.
Keep the complete visible marking, source brand, package label, invoice reference and the evidence filename tied to the same request line.
Describe the cross-section or tooth form, count every rib or tooth and photograph the profile. Do not infer a code when the geometry is unclear.
Record width and any printed length designation. For a measured length, add the unit, method and whether the outside, effective, datum or pitch basis is actually known.
Separate observed, supplied, measured, catalog-supported and still-unknown fields so a candidate result cannot be mistaken for approval.
Narrowing the expected drive system, product family and catalog context.
That the removed belt or current package is the correct part for the vehicle.
Finding a source record, preserving a suffix or distinguishing similar references.
A current cross-reference, supersession or destination-market fitment.
Separating broad V-belt, V-ribbed and synchronous-belt candidates and checking geometry.
Length, construction, pulley compatibility or vehicle application.
Checking a candidate against a stated method, unit and family-specific basis.
Interchangeability when the length basis, profile or application evidence differs.
Retaining markings, profile, condition, count, measurement setup and package identity.
Material, performance, manufacturing source or unseen dimensions.
Official standards describe different automotive belt families with different dimensional contexts. ISO 2790 covers automotive V-belts and corresponding pulleys, ISO 9981 covers automotive PK V-ribbed belts and pulleys, and ISO 21342 includes synchronous-belt pitch spacing, tooth dimensions, width and pitch length. Use those distinctions to preserve the measurement basis, not to claim that an unverified belt complies with a named standard.
Automotive V-belts and corresponding pulleys for auxiliary drives have a family-specific dimensional scope.
Review official abstractAutomotive PK V-ribbed belts and pulley grooves have a defined profile and dimensional context.
Review official abstractAutomotive synchronous belts use pitch, tooth, width and pitch-length characteristics together.
Review official abstractKeep the printed designation and measurement method intact. Ask the reviewing catalog or supplier to explain any conversion or candidate match.
The existing blank RFQ CSV already separates source identity, application, profile, count, dimensions, commercial scope, evidence and open questions. Preserve unknown values instead of filling them with an assumed code.
Identification evidence supports candidate review. It is not a DNK fitment, interchange, standard-compliance or performance guarantee.
Frequently asked
In the example 6PK1003, 6 is the rib count, PK identifies the automotive V-ribbed profile, and 1003 is the effective length in millimetres. Keep the manufacturer's part number and any suffix with the size marking when requesting a replacement.
No. Preserve the complete marking and source brand, then review it with vehicle or engine data, destination market and catalog evidence. A marking can identify a candidate record but is not final fitment approval.
Send the vehicle or equipment application, current package or invoice reference, full-belt and profile photos, rib or tooth count, width, any known length designation and how a physical measurement was taken. Keep unreadable fields marked as unknown.
Not necessarily. Profile, tooth or rib geometry, length basis, construction, application and pulley system can differ. Similar physical observations narrow a review; they do not establish interchangeability.
Preserve the printed designation first. If you also measure the belt, record the value, unit, method, equipment and whether the basis is known. Do not silently convert or mix outside, effective, datum or pitch-length values.
Include the complete belt, the full readable marking, ribbed or toothed profile, cross-section where practical, count evidence, width or measurement setup and the package label. Name each file so it can be linked to the request line.
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