Buying a Replacement Conveyor Belt: By the Metre, Markings and the Mistakes That Cost Money

A few years ago a new roll of belt was standing in the yard of an arable farm out on the plains, and the manager was proud of the price. Bought by the metre, ordered cheap, cut to width down to the millimetre. What nobody read was the marking on the inside. The new belt had a thinner carrying-side cover than the old one, and after a single summer it was worn through where the old belt had lasted three years. The cheap metre turned out to be the expensive one.

The cheap metre that turned expensive

The mistake at that farm was not the low price. The mistake was that nobody checked what was actually coming off the roll. A belt does not become expensive because it costs a lot to buy. It becomes expensive when it has to come off again too soon.

Cost a belt purchase honestly and there is more on the bill than the price per metre: the belt itself, the fitting and the splice at the ends, every repair to that seam over its life, and the production you lose while it is being repaired. The price is what you pay. The cost is what you end up spending.

One belt manufacturer puts the gap at four to five times the service life between quality goods and a bargain belt. That is a manufacturer’s figure and not a standard, but the direction matches what you see out in the field: a cover one grade better suited to the material can save a whole replacement cycle. A replacement saved is not just a belt saved. It saves the downtime along with it, and the downtime is usually the dearer item.

That is the thread running through this article. Save at the wrong end of a belt and you pay for it at the transfer point. And nearly every one of those false economies can be headed off at the order stage, once you know what matters.

Cut-to-length or fabricated: what you are really buying

Conveyor belt comes in two basic forms, and the choice decides how much work and risk stays with you. Belt by the metre is belt off the roll, cut to the length you want and often to the width you want, with open ends. A fabricated belt is joined endless and ready to run, made to size and delivered fit for service, on request already fitted with cleats, guide profiles or sidewalls.

Buying belt by the metre is a bit like buying cloth off the bolt. The metre is cheap, but you cut and hem it yourself. Hemming here means joining the two ends into an endless belt. If the goods are also slit lengthwise from a wider roll, the carcass lies open along that cut edge, where a full-rubber sealed edge would normally sit. Moisture wicks into the fabric through an open edge.

Which form pays off depends less on price than on your workshop. If you can splice cleanly yourself, or have a service firm on call, belt by the metre serves you well and you keep a length in stock. If you need the belt ready to run and do not want to answer for the splice, you buy fabricated and pay for that peace of mind. Both are right, just for different operations.

The marking is your order

Every proper belt says what it is. That designation is not printed for show, it is the specification you order by. Order by looks, that is by colour, thickness and feel, and you often order the wrong thing. Read the designation and you order what fitted last time. No serious manufacturer sells you a belt on colour alone, and no good dealer fails to ask for the building blocks below.

Take a typical designation like EP 400/3 4+2 Y apart. It looks like a number plate, and that is exactly how it reads, block by block.

The number in the middle causes the most confusion. The 400 in an EP 400 is not the number of plies and not the thickness, it is the belt’s nominal breaking strength. Common textile belts come in steps such as EP 250, EP 400, EP 500, EP 630, EP 800 and higher, usually through more or stronger plies. For buying, one thing counts above all: know the old designation when you reorder and you save yourself the guesswork and the supplier a query. If the embossing is no longer legible on the old belt, a photo of an offcut often helps more than a long description.

Here we read the designation as an order: what do I order so the new belt matches the old one. What the individual fabrics and cover grades mean for behaviour in service, which compound lasts longer with which material, is a question of belt type and a chapter of its own.

The splice: the weakest point in the purchase

With belt by the metre you buy the belt, you do not buy the splice with it. The open ends are either hot-vulcanised, that is pressed under heat and pressure into a continuous, homogeneous seam, or joined mechanically with fasteners and clips. A vulcanised splice holds longer and tighter, but it takes longer and needs equipment. A mechanical one is quick and needs little tooling, but it is the more delicate solution as soon as tension and tightness come into play.

For the purchase, only one thing counts: the splice is the weakest point in the whole belt. A strong belt with a badly made seam is a weak belt. So anyone ordering belt by the metre should know beforehand who joins the ends and with what, not once the roll is already sitting in the yard. Which method is right when, how long a splice lasts and what it costs is a subject in its own right.

Weight and roll: what actually gets delivered

Say conveyor belt weight and most people think of the tonnage on the belt, not of the roll in the yard. Yet it is the roll weight that decides the logistics of the purchase. A conveyor belt is heavier than it looks. One millimetre of cover rubber weighs around 1.12 kilograms per square metre, so a cover package of 4 plus 2 millimetres already brings nearly 6.7 kilograms per square metre in rubber alone. On top comes the carcass at 4.2 to 5.5 kilograms per square metre depending on the construction.

For the total weight there is a usable rule of thumb: total thickness in millimetres, times width in metres, times length in metres, times 1.45, gives the weight in kilograms. A belt 800 millimetres wide, 100 metres long and 12 millimetres thick comes to around 1,400 kilograms that way. That is the roll that has to be delivered, unloaded, lifted and stored. It weighs about as much as a small car, except a small car has wheels.

A roll is soon wider and heavier than any workshop door would like. A heavy, awkward roll ties up a crane or forklift, floor space to manoeuvre in and a few strong pairs of hands. Work that out only on delivery day and you have a problem on delivery day. Settle beforehand how the roll comes off the lorry and how you move it to where it goes in. The right lifting gear is cheaper than a roll that sits in the way because nobody can lift it.

Storing without losing service life

Rubber ages even when the belt only sits on the rack and never runs a metre. Ozone and UV light keep working, and the compound turns more brittle with the months. A belt in the store is like a rubber band in a drawer. You never use it, and it still snaps one day at the first firm pull.

You store it best lying flat or hanging, free of tension, dry and out of the sun, at around 10 to 20 degrees. As a rule of thumb, keep the storage time to no more than six months, and under ideal conditions up to eighteen months. After that you are not fitting a fresh belt at all, you are fitting an aged one.

For the purchase this means: over-buying belt by the metre is not a saving but capital tied up with an expiry date. The roll you lay in as a reserve ages on the rack too, and the handsome spare may already be past its best by the time of the next fit but one. A little reserve is sensible. Half a warehouse of belt rarely is.

The mistakes that cost money

In the end, the expensive mistakes in buying belt come down to the same handful of patterns. They rarely cost anything at purchase. They cost later.

The first is buying by feel instead of by designation. Two belts can look the same and differ sharply in carcass, cover thickness and abrasion grade. Someone who does not know the old designation and reorders by looks soon buys the weaker goods, exactly as on that farm.

The second sits in the carrying-side cover. If the top cover is too thin for the material, it is worn through quickly, and then the carcass lies exposed. A belt with an open carcass runs on borrowed time: the fabric draws moisture, frays and comes apart ply by ply. Carrying-side cover thickness is no side issue, it is your real reserve of service life.

The third mistake sits in the pulley, not the belt. A thick, stiff carcass needs a big enough pulley to run around without damage. The seemingly stronger belt on too small a pulley gets over-bent, the plies separate, and it tears sooner than a properly chosen one. Stronger is simply not automatically more durable. Belt and pulley need to be thought of together, at the latest when you order a higher strength class than before.

The fourth is over-buying, which has already come up: too much belt by the metre in reserve ages on the rack; too little, or the wrong width, means a reorder, fresh freight and downtime until the right roll arrives. Both cost money, and both can be avoided with a clean order.

And the most expensive mistake is the one we started with: taking the price per metre for the whole truth. The price is on the invoice. The cost turns up a year later at the transfer point.