How do I read a timing belt part number like 800-8M-30?
Direct answer: 800-8M-30 means 800 mm pitch length, 8M tooth profile on an 8 mm pitch, and 30 mm width. Metric codes read length first, then profile, then width; imperial codes put the profile letter after the length in inches and the width in hundredths of an inch.
Decoding metric and imperial codes
| Code | Pitch length | Profile | Width |
|---|---|---|---|
| 800-8M-30 | 800 mm | 8M, 8 mm pitch | 30 mm |
| 2320-14M-40 | 2320 mm | 14M, 14 mm pitch | 40 mm |
| 320L075 | 32.0 in (812.8 mm) | L, 3/8 in pitch | 0.75 in (19.05 mm) |
| 120XL025 | 12.0 in (304.8 mm) | XL, 1/5 in pitch | 0.25 in (6.35 mm) |
| 450H100 | 45.0 in (1143.0 mm) | H, 1/2 in pitch | 1.00 in (25.4 mm) |
Common profiles and their pitches
| Profile | Pitch | Typical use |
|---|---|---|
| MXL | 2.032 mm | Small instruments and light drives |
| XL | 5.08 mm | Light duty machinery |
| L | 9.525 mm | General light industrial drives |
| H | 12.7 mm | Medium load drives |
| 3M / 5M / 8M / 14M | 3 / 5 / 8 / 14 mm | Metric drives from light to heavy duty |
| AT, STD, RPP | Metric, modified tooth form | Higher load, quieter running, positioning drives |
Why the length on the belt is not what you measure
Timing belt length is the pitch length, measured along the cord line inside the belt. A tape run around the outside gives a different number, and a worn or stretched belt reads longer than its code. If the marking has gone, measure the width and count the teeth: pitch length equals the number of teeth multiplied by the pitch. A 1624 mm 8M belt therefore has 203 teeth.
How to specify a belt when the code is worn off
- Measure the belt width across the flat back, in millimetres.
- Count the teeth over the whole belt, then multiply by the pitch to get the pitch length.
- Identify the profile from the pulley, not from the old belt, because a worn belt can look like a different tooth form.
- Send one photo of the belt marking and one of the pulley tooth profile and we will confirm the match.
Send the code and we will match it
Email the belt code, a photo of the belt and one of the pulley tooth profile, plus the quantity, to sales@goodlybelts.com. We will confirm the profile and length and quote the equivalent GOODLY belt.
Check my belt code
Are you looking for a reliable manufacturer of conveyor belt products?
We can quickly provide customers with market analysis, technical support and customized services.- Name
- Phone
- *Title
- *Content