A worn sprocket can damage a new belt in weeks. Replacing it correctly starts with a complete drawing.
A replacement conveyor sprocket can be made from a complete, accurate drawing showing outside diameter, number of teeth, pitch and tooth form, bore, keyway, thickness and material, plus the mating belt or chain. An old sprocket sample helps but is not always necessary. The sprocket is reviewed against the belt and shaft before production.
We are YIYI Mesh Belt, a metal conveyor belt manufacturer in Ningjin, Dezhou City, Shandong Province, China. Our manufacturing experience dates back to 1998, and we work on a 27,000 m² site with about 280 units of production and supporting equipment, including 9 welding robots. I am Sunny Ye. We supply Drive Sprockets and Related Conveyor Components matched to the belt, shaft and equipment. Sprocket manufacturing is a specialist process; we control the specification, the review and the finished-product checks.
At a Glance
| Product | Drive Sprockets and Related Conveyor Components |
|---|---|
| Technical basis | A complete, accurate drawing; old sample helpful but not always required |
| Key data | OD, number of teeth, pitch, bore, keyway, thickness, material, mating belt or chain |
| Materials | SUS304, SUS316, carbon steel, UHMW-PE, nylon or POM, depending on project |
| Manufacturing | Specialist external process; YIYI controls specification, review, finished QC and packing |
What Must a Sprocket Drawing Show?
A usable sprocket drawing shows outside diameter, number of teeth, pitch and tooth form, bore diameter and tolerance, keyway size, hub and plate thickness, material and quantity, and names the mating belt or chain. With those values complete and accurate, the drawing can be the technical basis for a replacement without the old part.
| Item | Why it matters |
|---|---|
| Outside diameter (OD) | Fit in the machine; belt wrap |
| Number of teeth | Belt speed and engagement |
| Pitch and tooth form | How teeth meet the belt or chain |
| Bore and tolerance | Fit on the shaft |
| Keyway | Drive transmission |
| Thickness / hub | Position on the shaft; strength |
| Material | Wear, corrosion, food environment |
| Mating belt or chain | Engagement must match |
Sunny's view: If the drawing does not name the belt it drives, add it. Pitch on paper means little without the belt next to it.
When Does an Old Sprocket Sample Help?
An old sample helps when the drawing is missing, incomplete or old, when tooth form is hard to describe, or when wear marks can show how the belt actually engaged. It is not always required: a complete, accurate drawing can be enough. Worn teeth are measured with care, not copied.
- No drawing: the sample is the main evidence; measure OD, teeth, bore, keyway and thickness.
- Old drawing: the sample shows whether the machine was changed since.
- Tooth form: photos side-on show the profile better than words.
- Wear marks: show which face of the tooth carried the load.
Hooked or polished teeth are worn; measure tooth form on the least worn teeth, or from the drawing, rather than copying the worn shape.
Sunny's view: Photograph the old sprocket side-on with a ruler, and one tooth close up. Those two photos often settle the tooth form.
Why Must the Sprocket Be Matched to the Belt?
The sprocket drives the belt or chain through its teeth, so pitch, tooth form and position must match the belt. A mismatch causes noise, jumping, uneven wear and damage to a new belt. That is why we review the sprocket with the mating belt or chain, and with the shaft, before production.
- Flat Wire / Honeycomb, Balanced Weave and other sprocket-driven belts: tooth pitch and form to the belt pitch
- Chain Driven and Chain Plate belts: sprocket to the chain pitch and roller
- Eye Link Belt: sprocket to the roller chain edge
- Spiral and side driven belts: drive components to the equipment interface
When a belt is replaced, check the sprockets too; when a sprocket is replaced, check the belt. Read how to choose the chain for a chain driven belt.
Sunny's view: New sprocket, old belt, or new belt, old sprocket: both can go wrong. Review them as a pair.
Which Sprocket Material Should You Choose?
Depending on the project, sprockets can be made in SUS304, SUS316, carbon steel, UHMW-PE, nylon or POM. Metal suits higher loads and heat; plastics suit some food and wet lines where lower friction and noise matter. The choice depends on load, temperature, cleaning, the belt material and the existing machine.
| Material | Typically reviewed for |
|---|---|
| SUS304 / SUS316 | Food and wet lines, washing, corrosion resistance |
| Carbon steel | Dry industrial lines |
| UHMW-PE, nylon, POM | Some food and wet lines; lower noise; temperature confirmed per project |
Match the sprocket material to the belt and the environment. Plastic sprocket material and temperature suitability are confirmed per project.
Sunny's view: If you change sprocket material, tell me why. Noise, wear and corrosion lead to different choices.
How Are Replacement Sprockets Made and Checked?
Sprocket manufacturing is a specialist external process. We control the requirement and drawing, review dimensions, carry out finished checks, review matching with the belt and pack the parts. Checks include tooth and contact finish, bore, keyway, thickness and visible burrs or damage, and for plastic parts, scratches and contamination.
Finished checks
- Metal: tooth and contact finish, bore, keyway, thickness, burrs or damage, no unacceptable grind marks
- Plastic: scratches, black contamination, excessive burr, bore burr
We do not claim a running test for a sprocket without the actual operating conditions. Where a sprocket is supplied with a belt, matching between the two is part of our review.
Sunny's view: Check the bore and keyway on your shaft before installation. Five minutes with a caliper can save a day of downtime.
What Should You Check When Installing a New Sprocket?
Before fitting, check the bore and keyway against the shaft, the tooth count and pitch against the belt or chain, and that both sprockets on a shaft are the same and aligned. After fitting, run slowly and watch engagement: teeth should enter the belt or chain smoothly, without climbing, noise or side load.
- Bore and keyway fit the shaft without forcing
- Tooth count and pitch match the order and the belt
- Sprockets on the same shaft are identical and lined up
- Set screws or locking as the equipment builder specifies
- Slow test run: smooth engagement, no climbing or noise
Note the date of fitting and the order number of the sprockets in the maintenance log, so the next replacement can be planned.
If the belt is old and the sprocket new, watch closely in the first days. A stretched belt on a new sprocket may not engage cleanly; replacing both together is often the better choice.
Sunny's view: Run the belt slowly for a few minutes after fitting and watch one tooth through a full revolution. Problems show quickly.
Should You Keep Spare Sprockets?
For critical conveyors, a set of spare sprockets matched to the belt shortens repairs. Order them with the belt or with the replacement sprockets, from the same drawing, so they fit without review. Store them clean and dry, labelled with the drawing number and the conveyor they belong to.
- Order spares from the same drawing as the installed sprockets
- Label them with the conveyor and drawing number
- Store them clean, dry and protected from damage to the teeth
- Check them before use like a new part
Keep worn sprockets you remove until the new ones have run well; they are useful evidence if a question comes up.
Spare sprockets, spare belt sections, rods and other components can be supplied on a project basis as Drive Sprockets and Related Conveyor Components. Read how to maintain and repair a metal conveyor belt.
Sunny's view: A spare sprocket on the shelf costs little. A stopped line waiting for one costs a lot more.
What Should You Send to Order a Replacement Sprocket?
Send the drawing with OD, number of teeth, pitch, bore, keyway, thickness and material, the quantity, the mating belt or chain model and pitch, shaft and equipment details where relevant, and photos or a sample of the old sprocket if available. Missing items can be measured from a sample.
Checklist
- Drawing, or measurements: OD, teeth, pitch, bore, keyway, thickness
- Material
- Quantity
- Mating belt or chain: type, model, pitch
- Shaft and equipment information where relevant
- Old sprocket photos (side-on, tooth close-up) or a sample
Read what parameters you need to replace a metal wire belt and when to replace the belt and sprockets together (yiyimeshbelts.com).
Sunny's view: If you are ordering a belt, add the sprockets to the same inquiry. Reviewing them together is faster and safer.
When This Is Not the Right Approach
Do not order a sprocket from a number of teeth and a bore alone. Pitch and tooth form must match the belt or chain, or the new sprocket will wear the belt.
And do not copy a badly worn sprocket. Worn teeth are evidence of wear, not the original design.
From Our Engineering Experience
Sprocket inquiries are often part of a belt replacement. The most common gap is the mating belt or chain information; with that, most drawings can be reviewed quickly.
We supply sprockets as Drive Sprockets and Related Conveyor Components, made by specialist partners to our specifications and checked by us before packing.
FAQ
Can you make a sprocket from a drawing alone?
Yes, if the drawing is complete and accurate. An old sample helps but is not always required.
What must the drawing show?
OD, number of teeth, pitch and tooth form, bore, keyway, thickness, material and the mating belt or chain.
Which materials are available?
SUS304, SUS316, carbon steel, UHMW-PE, nylon or POM, depending on the project.
Do you make the sprockets yourselves?
Sprocket manufacturing is a specialist external process; we control specification, review, finished checks and packing.
Should I replace sprockets with the belt?
If teeth are hooked or polished, yes. Review belt and sprockets as a pair.
Conclusion
A complete drawing and the mating belt are the basis for a replacement sprocket. Review the pair, choose the material for the line, then check before installing.
Need replacement sprockets?
Send the drawing or measurements, material, quantity and the mating belt or chain. We review the sprocket with the belt before production.
See sprockets and components →WhatsApp Sunny📄 Chain Driven Belt RFQ Application Sheet (PDF) · Email: info@yiyimeshbelt.com
Related reading: How to choose the chain for a chain driven belt · Parameters to replace a metal wire belt · How to maintain a metal conveyor belt · How to match sprockets and conveyor belts (yiyimeshbelts.com)
Sunny Ye
Global Sales Director, YIYI Mesh Belt · 15 years in metal conveyor belt projects
I work with spiral freezer builders, distributors and plant teams on belt selection and replacement. Questions about this article? Send them to me directly.
Follow Sunny on LinkedIn · Last updated: 2026-10-15
