A cracked weld on one link can look minor. On a self-stacking belt it weakens the support for every tier above that point.
Weld cracks on Self-Stacking Belt links usually come from weld quality problems such as burn-through or poor fusion, fatigue from repeated loading in the turn and the stack, overload, or corrosion at the joint. Find which one applies before replacing the belt; a copy built the same way can crack in the same place.
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. Weld cracks are, with deformed stack plates, the damage we see most often when buyers send old self-stacking belts for review. This is how we read them.
At a Glance
| Problem | Cracked welds at links, rod ends or stack plates on a Self-Stacking Belt |
|---|---|
| Common causes | Weld quality (burn-through, poor fusion), fatigue, overload, corrosion at the joint |
| Why it matters | A cracked joint weakens support for the tiers above and can spread |
| First checks | Where the cracks are, how many, weld appearance, load, cleaning chemicals |
| What to send | Close-up photos of cracks, their position, product load, cleaning routine, a section of the old belt |
Where Do Weld Cracks Usually Appear?
Cracks usually appear where load and movement meet a weld: the joint between link and rod end, the weld that fixes a stack plate, and the links on the inner edge that collapse in every turn. The pattern shows whether the weld or the load is the cause.
| Location | What it often points to |
|---|---|
| Link-to-rod welds along the whole belt | Weld quality or a weld design problem |
| Inner edge links | Fatigue from collapsing and opening in every turn |
| Stack plate welds on lower tiers | Overload from the stack above |
| Welds with rust or discoloration | Corrosion at the joint, cleaning chemicals, heat tint |
| A single section | A repair, a different batch, or local damage |
Map where the cracks are before anything else. The pattern usually tells you whether to look at the belt, the load or the freezer.
Sunny's view: Send me the crack map, even as a sketch. Ten cracks spread evenly mean something very different from ten cracks in one metre.
How Does Weld Quality Cause Cracks?
A weld that burns through the base metal, does not fuse fully, sits in the wrong position or is left with sharp edges creates a weak point. Under repeated loading those points crack first. Burn-through thins the metal around the joint; poor fusion leaves the joint held by a small area; sharp points concentrate stress.
- Burn-through: too much heat melts away base metal, leaving a thin or holed joint.
- Poor fusion: too little heat leaves the weld sitting on the surface rather than joined into it.
- Wrong position: a weld placed where the joint flexes takes more stress than designed.
- Rough finish: sharp points and spatter concentrate stress and trap residue.
Consistent welding prevents most of this. We run 9 automatic welding robots and use robotic welding where applicable, and weld quality, smooth and rounded weld points are part of our 100% final inspection. Read how robotic welding improves consistency.
Sunny's view: Look at a cracked weld from the side. If the weld bead sits on top like a drop of water, it probably never fused properly.
Why Does Fatigue Crack Welds in a Self-Stacking Belt?
In every turn, inner edge links close and open, and stack plates take load as tiers stack and unstack. Over thousands of cycles, even a sound weld can crack if the joint flexes more than it was designed for. Tight turns, heavy load and uneven stacking add to it.
Fatigue cracks often start small, at the edge of the weld, and grow along the joint. They are typical on inner edge links and on plates that seat unevenly.
- Turn ratio: a belt running tighter than its design flexes more at the inner edge. Our Self-Stacking Belt references a turn ratio of 1.6 / 1.7.
- Uneven stacking: a plate that seats at one corner flexes its weld on every cycle.
- Speed and load: more cycles and more load mean more fatigue.
If cracks follow the inner edge, review the turn and stacking along with the belt. Read what causes side plate deformation.
Sunny's view: Fatigue cracks are a message about the machine as much as the belt. Ask what changed: speed, product, or the freezer itself.
How Does Corrosion Lead to Weld Cracks?
Welds are where corrosion often starts: heat tint from welding, crevices at the joint and residue trapped there all weaken the protective surface of stainless steel. Chlorides from salt, brine or cleaning chemicals attack those spots. Corrosion pits at a weld become starting points for cracks under load.
- Rinse cleaning chemicals off completely, especially chlorinated ones
- Remove residue from joints before it dries
- Review SUS316 where salt or brine is present
- Consider pickling where the project requires it, to remove heat tint after welding
Pickling and electropolishing are carried out by specialist partners under our project specifications. Read why stainless steel belts rust and pickling or electropolishing.
Sunny's view: Rust at welds and cracks at welds often appear together. Treat them as one problem and look at cleaning first.
How Are Weld Cracks Prevented in Production?
Prevention starts with the weld: controlled parameters and fixturing, robotic welding where applicable, welds placed where the drawing puts them, and weld points finished smooth and rounded. A trial section and complete first article confirm the joints before mass production, and every belt receives a 100% final inspection before packing.
- Incoming wire and rod checked against Material Documentation, with spectral and hardness testing
- Wire and round bar drawn in-house where applicable, with diameter checks
- Welding parameters and fixtures set for the joint; robotic welding where applicable
- Trial section and complete first article, including joint and edge checks
- In-process QC during production
- 100% final inspection: welding quality, smooth and rounded weld points, structural dimensions
Weld position is checked against the drawing, so welds sit where they do not interfere with the stack or the freezer.
Sunny's view: The first article is the right moment to look at welds closely. Ask for close-up photos of a few joints.
How Can You Inspect Welds During Maintenance?
Inspect welds at each planned stop: look along the inner edge links and stack plate welds in good light, check for rust marks or dark lines at joints, and run a gloved hand along edges. Record what you find with dated photos. Early cracks are far easier to deal with.
- Inner edge links: look for fine lines at the edge of welds.
- Stack plate welds: check the lower tiers first, where load is highest.
- Rust marks: brown lines at a joint often show a crack or crevice.
- Movement: a joint that moves when the belt runs slowly is cracked through.
- Records: dated photos of the same joints show whether cracks grow.
Combine weld checks with plate and edge checks, because cracks, deformation and corrosion often appear together. Read how to maintain and repair a metal conveyor belt.
If cracks appear soon after installation, report them with photos and the order number. We review them against the production and inspection records for that belt.
Sunny's view: Pick ten joints on the inner edge and photograph them every month. If anything changes, you will see it before it becomes a stop.
What Should You Do When You Find Cracked Welds?
Stop and assess before running further: count and map the cracks, photograph them close up, check the load and cleaning routine, and send the evidence with a section of the old belt. A few cracks may be repairable with matching spares; widespread cracking usually means replacement, after the cause is found.
Steps
- Map the cracks: tier, edge, distance between them.
- Photograph each type of crack close up, with a ruler.
- Note product load, speed, cleaning chemicals and any recent changes.
- Send the evidence and a section of the old belt.
- Decide repair or replacement once the cause is known.
Running a belt with spreading cracks risks a break in the stack. Follow the equipment builder's safety instructions for stopping and inspecting the freezer.
For replacement, read how to select a self-stacking belt and OEM or direct supplier for a replacement.
Sunny's view: A short video of the belt passing a cracked area, running slowly, often shows whether the joint is moving. Send it with the photos.
When This Is Not the Right Approach
Do not weld over cracks in place on a running freezer belt without the equipment builder's approval. Field repairs can add heat tint and stress next to the old crack.
And do not assume a thicker link will solve fatigue. If the turn or the stacking is wrong, a stiffer link can move the crack to another joint.
From Our Engineering Experience
When buyers send self-stacking belts for review, we look at cracks together with plate deformation and corrosion, because they often share a cause. The question we ask is always: what would make the same belt crack again?
The field photos in this article come from belts sent to us for review. They are not YIYI belts, and we do not name their makers.
FAQ
Why are the welds on my self-stacking belt cracking?
Common causes are weld quality problems, fatigue in the turn and stack, overload and corrosion at the joint.
Where do weld cracks usually start?
At link-to-rod joints, stack plate welds and inner edge links that flex in every turn.
Can cracked welds be repaired?
A few may be repaired with matching spares; widespread cracking usually means replacement once the cause is known.
Does robotic welding prevent cracks?
It improves consistency; weld design, load, turn and cleaning still matter.
What should I send for a review?
Close-up photos and a map of the cracks, load and cleaning details, and a section of the old belt.
Conclusion
Weld cracks come from weld quality, fatigue, overload or corrosion. Map them, find the cause, then repair or replace with a belt built to avoid it.
Finding cracked welds?
Send close-up photos, a crack map, the product load and cleaning routine. We review the cause before recommending repair or replacement.
See Self-Stacking Belt specifications →WhatsApp Sunny📄 Self-Stacking Belt RFQ Application Sheet (PDF) · Email: info@yiyimeshbelt.com
Related reading: Side plate deformation causes · How to avoid weld burrs · How to select a self-stacking belt · What causes self-stacking belt failure (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
