Timing Belts – Procedure for Belt Identification
What timing belt do I have? We have prepared a guide to identify timing belts. Marking on a broken belt is not always visible.
Following Steps
- Step 2 – What Is the Material of the Timing Belt? Rubber or Plastic?
- Step 3 – What Is the Timing Belt Type and Pitch?
- Step 4 – What is the Timing Belt Length? Timing Belt Length = Number of Teeth!
- Step 5 – What is the Timing Belt Width?
- More Tips for Timing Belt Identification
Previous Step
- Step 1 – What Sort of Belt Do You Have?
Do You Need a New Timing Belt?
Order your timing belt right in our eshop!
Step 2
What Is the Material of the Timing Belt? Rubber or Plastic?
Common timing belts are made of two different materials...
... rubber = black, ordinarily of fibreglass...
... and polyurethan = light plastic, ordinarily of steel fibre.
Step 3
What Is the Timing Belt Type and Pitch?
Rubber belts with rounded teeth (HTD), measurements are generally given in mm...
... whereas with squared teeth, measurements are given in inches...
... and less common, there are belts with a rounded tooth with a flat top – STD (upper belt).
Pitch is measured from the right edge to the right edge of two adjacent teeth, e.g. 9.53 mm = 3/8 in (belt type L)…
... or from the centerlines of two adjacent teeth, e.g. HTD pitch = 8 mm...
... or plastic belt pitch is 10 mm.
The Most Common Belt Types according to Pitch
- HTD: 3M, 5M, 8M, 14M
- STD: S3M, S5M, S8M, S14M
- Inch Sizes: MXL, XL, L, H, XH, XXH
- Polyurethane: T, AT
Step 4
What is the Timing Belt Length? Timing Belt Length = Number of Teeth!
Do not measure the length of the belt with a cord, this is inaccurate!
The surest method is to count the teeth.
Mark the tooth where you begin counting...
... preferably, mark every 10th tooth thereafter.
Belt length = no. of teeth × belt pitch.
Or you can look up the number of teeth in our belt catalogue.
Step 5
What is the Timing Belt Width?
Measure the width of the belt, e.g. 16 mm…
... or measure the belt in inches, e.g. 19.05 mm = 3/4 in, i.e. belt type 075.
More Tips for Timing Belt Identification
Newer belts have markings identifying product number and manufacturer...
... aiding you in determining the right belt type...
... or allowing our technicians an easy identification.
For manufacturing reasons, width is not usually marked on newer belts and it is necessary to measure it before ordering!
Note the difference between belt types T and AT.
T teeth fit together...
... whereas AT teeth do not.
Special belts can have a Kevlar fibre reinforcement, as shown here in this belt cord.
Timing belts for garden machinery (often double-sided) are typically STD…
.... belts with a rounded tooth with a flat top – STD (upper belt).
Does Timing Belt Damage or Breakage Happen Again and Again?
It is necessary to remove the belt and determine its fault! Use our unique troubleshoot guide. You can find there main potential causes of drive belt failure that are possibly damaging your belt, shortening its lifespan, etc. Simultaneously, there are instructions on how such problems may be solved.
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