A timing belt reference becomes much easier to read when you separate tooth pitch, profile, width and length. Each describes a different part of the product. This guide explains the fields used in catalogue comparisons and how to turn them into a practical service record for an existing synchronous drive.
Keep profile and pitch together
Pitch describes the spacing between teeth along the pitch line. The profile describes the tooth form used with the pulley. Record both rather than shortening a reference to a pitch number alone. Common catalogue families use letters and numbers to distinguish their geometry. The drive's original specification or approved parts record tells you which family belongs in that installation.
Understand width and pitch length
Width is measured across the belt. Pitch length describes the length along its pitch line and should be recorded using the catalogue's stated basis. In a synchronous belt, pitch length equals tooth pitch multiplied by tooth count when consistent units are used. For example, 110 teeth at a 5 mm pitch give a 550 mm pitch length. This arithmetic helps check a record; it does not select the tooth profile by itself.
Use tooth count as a checking field
A readable printed reference is usually the simplest starting point. Where tooth count is recorded, keep it alongside the stated pitch and width. A worn belt's outside measurement should not silently replace a catalogue pitch length. If a count or measurement disagrees with the reference, resolve that difference before turning it into a stock description. Photographing the original print helps preserve the evidence.
Keep machine context in the stock record
Record the machine, assembly, full belt reference, tooth profile, pitch, width, pitch length and quantity. Add any construction requirement stated in the approved specification. Use the machine and belt manufacturer's information for installation and tension values. Browse synchronous products by their complete fields, and keep a copy of the confirmed replacement reference for the next planned service.
Your specification checklist
Keep the following fields together for this drive. They give the next person handling the enquiry a clear record and make it easier to compare the catalogue description with the equipment information.
| Record | What to keep |
|---|---|
| Vehicle or equipment | Full model, relevant serial details and the installed engine or assembly. |
| Drive position | The component being driven, recorded separately from other belts on the machine. |
| Belt identity | The complete brand and printed reference, including prefixes and suffixes. |
| Specification | Profile, width and the relevant rib or tooth count from the listing. |
| Length basis | The catalogue's stated convention, retained alongside the numerical length. |
| Service record | Required quantity, previous replacement details and the applicable maintenance information. |
Common questions
Can two belts have the same pitch but different tooth forms?
Yes. Keep the profile designation as well as the pitch in the order record.
Can I calculate pitch length from tooth count?
Multiply the tooth count by the pitch using consistent units. Still confirm the full profile, width and construction required by the drive.
Explore the right belt range
Browse belt types and profiles and keep the complete specification alongside your order. The product listing shows the stated dimensions, reference and current availability.
Continue with Belt Families Explained: V, Wedge, Ribbed and Timing Belts, or explore more sizing and measurement guides. You can also return to the complete BeltIndex guide library.
Read a real catalogue specification
The Continental HTD550-5M9CXP listing shows pitch, width and tooth-count fields. Compare the format with a PIX 4PK663 ribbed-belt specification and a Dayco 10X0960 V-belt listing. These are examples of catalogue descriptions, rather than application selections for an unidentified machine.
Technical reference
Gates preventive maintenance manual provides manufacturer background. Use the equipment-specific service information for the actual installation and its specified settings.