QXG200 Single Conveyor Chain

Hangzhou Ocean Industry Co., Ltd. is one of the leading manufacturers and suppliers of qxg200 single conveyor chain in China. Welcome to wholesale bulk durable industrial chains and power transmission parts made in China here from our factory. All customized products are with high quality and competitive price.

The QXG200 is a 200 mm pitch single-rail overhead conveyor chain, and it is the size most painting and powder coating lines settle on when the load per hanger is too heavy for the light enclosed-track ranges but the line does not justify a dual-rail layout. It comes in three variants - QXG200-S, QXG200-HH and QXG200-HA - which share one pitch and one attachment interface but differ in wheel size, bearing type, allowable load and surface treatment.

The chain is the traction element of the loop. It does not carry the suspended load; the wheels running on the I-beam flange do. Separating those two jobs is what allows the same chain to serve a standard automotive primer line and an extra-heavy electroplating line without changing the track.

This page sets out the three variants and what separates them, how to read the specification table, what the forging and bearing choices actually buy you, where the chain suits a plant, how to specify a replacement, and how the order and shipment work. Figures come from the specification table; anything that depends on your own line is written as a question to settle rather than a number to copy.

The table below carries the reference data for all three variants. Read it as three related columns rather than three separate products, because the differences are progressive: each step up adds wheel diameter, bearing capacity, allowable load and a stronger surface treatment, while the pitch and the suspension geometry stay the same.

Two rows are easy to confuse and are worth separating here. Allowable tensile force is the working tension that may be applied along the line. Breaking tensile force is where it fails. On this range the breaking figure sits at roughly 1.7 to 1.9 times the allowable figure, so the working margin is carried inside the allowable value rather than sitting on top of it - which is why the allowable figure, not the breaking figure, is the one to size a line against.

Single lifting weight is a third quantity again: what one suspension point may carry. It is the number that decides how many hangers your process needs, and it is quite separate from what the chain can be pulled with.

Suspension spacing is written as 200+(200×N) on all three variants. That means hanger points sit at multiples of the pitch, so the process pitch you need is achieved by choosing N rather than by choosing a different chain.

The note under the table applies to all three columns: the figures are stated for standard test conditions of 20 °C and 60% relative humidity. A plant running through a curing oven at 220 °C, or a plating shop at high humidity, is outside those conditions, and the variant choice and the surface treatment should be settled with that in mind.

Note: figures are stated for standard test conditions of 20 °C and 60% relative humidity. Custom specifications are available on request; contact the engineering team for the full technical data sheet.

Five things separate this chain from a general-purpose overhead chain of the same pitch, and they are worth understanding individually because they fail independently and are replaced independently.

Drop-forged link plates rather than cut or stamped plates, which changes how the material behaves under repeated tension. Sealed wheel bearings rather than plain or grease-nipple wheels, which removes routine lubrication from the maintenance schedule. Articulated joints that flex in two planes, which is what allows a route with both horizontal curves and vertical bends without a transfer station. Three surface treatment grades, because a paint shop and a plating shop do not attack a chain in the same way. Interchangeable geometry across the three variants, so a capacity increase later does not mean replacing the track.

The rest of this section takes each of those in turn.

Each link plate is drop-forged from 40Cr or 45# alloy steel, then quenched and tempered under controlled conditions. The reason for forging rather than cutting the plate from flat stock is the grain structure: forging turns the material grain so that it runs with the direction of the tensile load instead of across it, and a fatigue crack has to work against that alignment rather than follow it.

That difference shows up in service as resistance to fatigue at the pin hole, which is where a link plate normally fails. Typical hardness is quoted as HRC 38–42 around the pin hole and HRC 42–46 at the wheel contact surface. The two figures are deliberately different: the pin hole wants enough toughness to resist cracking, while the running surface wants enough hardness to resist wear against the track.

The consequence for a buyer is that the plate is not a commodity item. Two plates of the same dimensions from two sources can have the same pitch and pin diameter and still behave differently over ten years of a three-shift line, because the difference is in the forging and the heat treatment rather than in the drawing.

One practical point on replacement. A worn QXG200 chain almost always fails at the pin hole rather than at the wheel, and a plate that is cracked at the hole is not visible from the side of the running line. Inspect the plates during a planned stop rather than waiting for a chain to part.

The wheel assemblies use double-sealed deep groove ball bearings, lubricated at assembly, on the standard and HH variants, and tapered roller bearings on the HA variant. The change from one to the other is not a cost decision; a tapered roller bearing takes a combination of radial and axial load that a deep groove ball bearing is not intended to take, and the HA variant is the one used where vertical bends put that combination into the wheels.

What sealed bearings buy you is the removal of routine greasing from the maintenance schedule. That matters more on this kind of line than it first appears, because the wheels on an overhead loop sit above the product and above the process equipment. A wheel that is being greased weekly from a ladder over a paint booth is a safety exposure as well as a labour cost.

Two absolute claims in the original specification are worth stating precisely. The wheels are sealed for life at assembly, which means no routine re-greasing is required under normal conditions - but a plant running an abrasive or high-temperature duty should still inspect seals on the schedule, because a damaged seal turns a sealed bearing into an open one. The quoted rolling friction coefficient is below 0.003 and the quoted noise figure is under 62 dB at rated load, both measured on new bearings under the test conditions noted above; a bearing at the end of its life will not hold either figure.

A high-temperature bearing option is available for duties up to around 300 °C, for oven sections that run hotter than the standard range allows.

The pin-and-bushing joint lets the chain flex in two planes. Minimum horizontal turning radius is R600 on the standard variant, R650 on HH and R700 on HA. Minimum vertical bending radius is R2500, R2800 and R3200 respectively. Those six numbers set the shape of the line before any other decision is taken.

The horizontal radius grows with the variant because the wheel diameter grows with it, and the wheel is what has to get round the curve. The vertical radius is larger by a factor of roughly four, which is why vertical bends are where a layout gets expensive: a single rise of a metre or two can consume several metres of approach on either side.

The practical benefit of two-plane articulation is that a route can be drawn as the process needs it rather than as the conveyor allows it. A loop can leave a loading station, run through a pre-treatment tunnel, turn through ninety degrees, climb to an oven at mezzanine height and come back down to unload, without a transfer point anywhere in the sequence. Every transfer point removed is a station that cannot jam and a component that does not have to be handled.

Where two planes meet - a horizontal curve at the same time as a vertical bend - both wheel sets share the load and the geometry is tighter than either radius alone suggests. If your layout has a combined curve and bend, send the drawing rather than the two radii: the interaction is what needs checking.

Three grades are offered, and choosing between them is about what the environment does to the chain rather than about how long you want it to last.

E-coating in black is the standard finish: an epoxy electrophoretic coating quoted at over 200 hours of salt spray resistance. It suits a dry finishing line - primer, base coat and clear coat stages in a vehicle plant, where the chain sees heat and paint overspray rather than liquid attack.

E-coating with zinc plating adds a sacrificial layer under the coating for humid environments. This is the grade for a plant with rinse zones, unheated buildings in a wet climate, or condensation cycles on a line that stops overnight.

Hot-dip galvanizing is for the hardest environments: outdoor runs, plating shops, and anything where the chain is exposed to process mist rather than to clean humidity. It is also the finish that stands up best to mechanical handling damage, because the coating is thicker and metallurgically bonded.

A point that is easy to miss when specifying: the finish has to be chosen for the worst station on the loop, not the average. A line that is dry for twenty metres and passes through one wet rinse zone will corrode at that zone and nowhere else, and the chain will be replaced for a reason that affects a small fraction of its length.

QXG200-S (Standard) is the starting point: 90 mm horizontal wheels, 70 mm vertical wheels, sealed ball bearing 6204, 40 kN allowable tension, 80 kg single lifting weight and E-coating. It suits a dry finishing line with a moderate load per hanger and no sustained vertical work.

QXG200-HH (Heavy-Duty H) steps the wheels to 100 mm and 80 mm, the bearing to 6205, the allowable tension to 50 kN and the single lifting weight to 100 kg, with E-coating plus zinc plating. The heavier bearing matters more than the heavier wheels: 50 kN is a 25% increase in allowable pull over the standard variant, which is the figure that lets a longer loop or a steeper vertical bend stay on a single rail.

QXG200-HA (Extra Heavy) is the variant for the hardest duty: 110 mm and 90 mm wheels, a tapered roller bearing 30204, 55 kN allowable tension, 120 kg single lifting weight, hot-dip galvanized, and a working temperature up to 250 °C against 200 °C on the standard variant. It is the one to specify where the line has both a heavy point load and a corrosive atmosphere.

The three variants are interchangeable at the link level: pitch, pin diameter and attachment interface are common across the range. That means a line can be upgraded from standard to heavy-duty by replacing chain links rather than by rebuilding the track - but the joints between old and new links are the part to plan, because a mixed chain has to be joined correctly and a partially upgraded loop has two different wear rates running in it.

The figures below are the ones worth holding on to when comparing quotations. They are stated in the original specification and reproduced here with the conditions attached.

Load. Up to 120 kg per suspension point on the HA variant, against a breaking tensile force of 95 kN.

Maintenance interval. Quoted as 12–18 months for bearings, in a normal finishing-line environment. That is an interval for inspection rather than a promise of no maintenance, and a plant running abrasive dust or a wet process should treat 12–18 months as the outside figure rather than the target.

Service life. Quoted as 8–12 years typical in automotive paint shop duty. The qualifier matters - that figure is for a clean, temperature-controlled, three-shift finishing line, which is the most favourable environment this chain runs in. A plating shop or an outdoor run will not deliver the same number.

Noise. Under 62 dB(A) at rated speed with new sealed bearings.

Energy. Low rolling resistance is quoted as reducing drive motor power consumption by 15–20% against a comparable chain. The comparison baseline is not stated in the source data, so treat this as an indicative figure rather than a measured saving for your line.

Installation. Modular link-by-link assembly, joined on site without special tooling.

The chain travels as an endless loop within a single-I overhead track. A drive unit - caterpillar or sprocket, depending on the line - is positioned at one point on the loop and engages the chain link plates or attachment pins, pulling the chain forward. The drive does not lift anything and does not support anything; it only overcomes the friction of the whole loop.

As the chain moves, the horizontal wheels run on the lower flange of the I-beam, turning the drive's rotary input into linear travel. Suspended loads hang from the attachment points, which sit at fixed spacing along the chain. Because the wheels are carrying the load and the chain is carrying only the pull, the two can be sized independently, which is the whole reason a chain of modest pitch can move a substantial load.

At the opposite end the loop closes through a return idler. A take-up device holds working tension and absorbs two things that change over time: the thermal expansion of the track and chain as the line heats and cools, and the gradual elongation of the chain as the pin holes wear.

The behaviour differs at the two kinds of bend. Through a horizontal curve the articulated joints let the chain follow the curve while the vertical wheels hold it on the track and prevent derailment. Through a vertical bend both wheel sets share the load, and the resultant force at that point is the one the chain absorbs as tensile load. That is why vertical bends, not horizontal curves, are usually what sets the variant for a given loop.

One consequence is worth stating plainly for anyone specifying a drive: on a long loop with vertical bends, the tension the chain carries at the drive is not the same as the tension it carries at the far end. The difference is what the bends and the gradients add, and it is the reason a drive sized from the load alone comes out marginal.

The clearest way to describe where this chain is used is to follow the part through the process, because the chain's job changes at each stage.

Loading and pre-treatment. Parts are hung at the load station, then travel through degreasing, rinse and phosphate or conversion coating. This is the zone that decides the surface treatment grade: rinse and mist are the reason the standard E-coat variant is sometimes not enough.

Electrodeposition. The dominant application for the 200 mm pitch range. Parts pass through the E-coat bath, and the chain works above a liquid tank rather than above a clean floor, in an atmosphere of process mist and changing humidity. Tank immersion zones are also where the vertical wheel arrangement earns its place, because it holds the chain on the track while the hanger passes through the bath line.

Primer, base coat and clear coat. Spray booths and their flash-off zones. The chain sees paint overspray, solvent vapour and heat. Access for gun cleaning and quality inspection is why a single-rail layout is often preferred over a dual-rail one on these lines.

Curing. The oven section. Temperature is the limiting factor here, not load: the standard variant is rated to 200 °C, HH to 220 °C and HA to 250 °C, and the track through this section needs its own expansion arrangement in addition to the right chain variant.

Cooling and unloading. The return leg. Loads come off, hangers are cleaned or exchanged, and the chain runs at its lightest for this part of the loop.

The same sequence describes the other industries the chain serves. In electroplating, the stages are zinc, nickel, chrome and decorative baths, and the whole loop sits in a wet, chemically active atmosphere. In appliance manufacturing - refrigerators, washing machines, air conditioners, microwave ovens - the stages are paint and finishing, and the load per point is typically well inside the range. General overhead handling, from warehouse storage and retrieval to garment and meat processing, uses the same chain where a single-rail layout is preferred for simplicity rather than because the load demands it.

Most QXG200 chain we ship goes onto lines that already exist rather than into new installations, so the practical question is usually which variant will do the job the present track is already doing - and occasionally whether the line can take a heavier one.

Replacing like with like. If the existing chain is a QXG200 variant and the track is sound, the variant on the line is normally the right one to order. Measure the pitch across several pitches and the wheel diameters before ordering, because a line that was upgraded once may be running a mixed chain that no longer matches its original specification.

Upgrading within the range. Where the load per hanger has risen but the track is in good condition, a step from S to HH, or HH to HA, increases the allowable tension and the single-point load without changing the pitch or the attachment interface. This is the cheapest way to gain capacity, because the track, the support steelwork and the drive position all survive.

When an upgrade is not the answer. If the limitation is the drive rather than the chain, a heavier chain does not help. If the limitation is the track section, a heavier chain may make it worse by putting more pull through the same curves. Work out which of the three - chain, drive or track - is actually the constraint before ordering anything.

When the duty has changed rather than the load. A line that has moved to a hotter oven, or that now runs a wet process where it used to run dry, may need a different variant and a different surface treatment without any change in load. Duty changes are as common a reason for replacement as wear is.

A painting or plating line is usually the bottleneck of the plant, so the replacement itself has to be planned around production windows rather than around convenience.

Measure before you order, not after. Take the pitch reading, the wheel diameters and a photograph of the track section. If the chain is a mixed assembly, photograph each joint. The order can then be placed while the line is still running.

Supply the chain in stages if the windows are short. A chain made up in the lengths each shutdown can absorb lets the loop be reopened with the new section already in place, so each window ends with the line running again, rather than with the project still open.

Plan the joints. The number of joints in a finished loop affects how the chain runs, so agree where they will sit rather than leaving it to the installation. Avoid placing a joint inside a vertical bend or at the tightest horizontal curve.

Re-tension after the first thermal cycle. A newly fitted chain settles and lengthens over its first weeks, and the loop length changes with temperature. The take-up stroke needs to be checked after the line has been through a full heat cycle, and again after the first month.

Check the track at the same time. Replacing a chain on a worn track is the most common way to shorten the life of the new chain. Track wear is concentrated at the curves, and it is cheap to inspect while the line is already open.

A quotation for a replacement chain is accurate to the extent that the information behind it is complete. The list below is what our engineers need; anything missing turns into an assumption, and an assumption about a conveyor is a risk the buyer carries.

Chain identification. The variant if known, or the pitch measured across several pitches and the wheel diameters if not. A photograph of a link, taken square-on with a ruler in frame, resolves most cases.

Track information. The I-beam section the chain runs on, and a photograph of the track at a curve if the line has one. This is what confirms the wheel geometry will suit the rail.

Loop and duty. Total loop length, the number of horizontal curves and vertical bends, the heaviest load on a single suspension point, and the number of loaded points on the line at once. Loop length and bend count are what determine whether one drive is enough.

Environment. The highest temperature the chain is exposed to, whether the line passes over open tanks or through mist, and whether the building is heated. These three answers settle the variant and the surface treatment.

Quantity and timing. Metres or number of links for the complete loop, plus any spare length, and the production window the line can be released in.

Attachments. The hanger or attachment interface, with a drawing or a sample if it is non-standard.

Payment terms on this product are T/T with a 30% deposit and the balance before delivery, and photographs of the finished goods are provided before the balance falls due. For orders above US$20,000, L/C is accepted.

An overhead conveyor chain is a heavy, awkward item to ship, and how it is packed determines how much of it arrives straight and usable.

Chain. Supplied in cut lengths or link sets, coiled or laid straight depending on the length and the transport mode, secured so that the chain cannot shift and abrade against itself in transit. Lengths are matched to the installation sequence where the line is being replaced in stages, and each bundle is labelled with its position in the loop rather than only with the order number.

Wheels and attachments. Packed separately from the chain so that the running surfaces are not damaged by the chain's own weight, and so that individual items can be taken to the point of use without unpacking a whole case.

Protection. The surface treatment is the part most easily damaged in transit, particularly on hot-dip galvanized goods. Bundles are separated and edge-protected so that coating damage happens, if it happens at all, where it is visible on receipt rather than at the far end of the loop.

Documentation. Packing list, and photographs of the packed goods before dispatch, so that a discrepancy is identified before the container is closed rather than after it is opened.

Mode. Sea freight for scheduled replacements, air or courier where a line is standing. We will say which of the two the order actually justifies rather than defaulting to the faster option.

The purchase price of a conveyor chain is a small part of what the chain costs over the life of a line, and the differences between variants are easier to judge on that basis than on the invoice.

Replacement interval. The largest single item is how often the loop has to be opened. A variant that runs two years longer between replacements saves not only the chain but the production windows, the installation labour and the risk of a line standing at the wrong moment.

Maintenance labour. Sealed bearings remove routine greasing from the schedule. On a long loop that is a recurring labour cost and a recurring safety exposure, because the greasing points sit above the process.

Energy. Rolling resistance shows up on the electricity bill continuously rather than once. The quoted reduction of 15–20% against a comparable chain is indicative rather than measured for a specific line, but the direction of the effect is real and it accumulates across every shift.

Track wear. A chain that runs true wears the track evenly. A chain with a damaged wheel, a wrong wheel diameter for the rail or an incorrect joint position concentrates wear at one curve, and replacing a track section costs far more than replacing the links that caused it.

Downtime. The item that usually dominates, and the one least visible in a quotation. A replacement planned into a scheduled shutdown costs the shutdown. A replacement that arrives as a breakdown costs whatever the line produces in the time it takes to recover.

Put against those five items, the difference between the standard and the heavy-duty variant is usually small, and the decision normally turns on the duty rather than on the price.

The QXG200 range is a standard product, and a good deal of what we ship is not. Where a line has an attachment interface that is no longer made, a pitch that no longer matches a catalogue, or a process environment the standard treatments do not survive, the answer is a made-to-order chain rather than a compromise on the standard one.

What can be customised. Non-standard pitch and link geometry, custom attachment and hanger interfaces, alternative bearing types for unusual loads or temperatures, stainless steel construction in 304 or 316 for chemically aggressive processes, and surface treatments outside the three standard grades. Engineering evaluation of a drawing or a sample normally takes about 48 hours, and the reply states what is feasible rather than what is convenient.

What we need to quote it. A drawing if one exists; failing that, a sample link plus a photograph and the key dimensions. For attachment work, the component that has to hang from it, or a drawing of the hanger, matters more than the chain dimensions do.

Samples. A trial length or a set of links takes roughly 30 working days to produce. A full production order follows in roughly 60 working days once the deposit is received. The two figures are the site-wide times we quote; a rush request can be discussed against actual stock, but we would rather quote the real figure than promise a date the shop cannot hold.

Why it stays in one place. Forging, heat treatment and assembly are in our own plant, so a non-standard attachment does not have to wait on a third party's tooling slot. That is the practical difference between a supplier who can modify a standard chain and one who can manufacture a non-standard one.

Q1: Do you manufacture the chain yourselves?

A: Everything on this chain except the bearings is made in our own plant, and the group has been producing chain since 2003. Technical questions are answered by the people who forge and assemble the product, not by a separate office.

Q2: How long is delivery for the QXG200 chain?

A: Allow roughly 30 working days for a trial length or a set of links, and roughly 60 working days for a full production order, both counted from the deposit.

Q3: What are your payment terms?

A: T/T with a 30% deposit and the balance before delivery, with photographs of the finished goods sent before the balance falls due. For orders above US$20,000, L/C is accepted.

Q4: Can the chain be customised?

A: Yes. Non-standard pitch, custom attachments, alternative bearings, stainless steel in 304 or 316 and non-standard surface treatments are all available. Send a drawing or a sample and engineering will come back in about 48 hours.

Q5: What is the difference between QXG200-S, HH and HA?

A: Wheel size, bearing type, allowable tension, single lifting weight and surface treatment. The standard variant carries 40 kN and 80 kg per point, HH carries 50 kN and 100 kg, and HA carries 55 kN and 120 kg with a tapered roller bearing. Pitch and attachment interface are common to all three.

Q6: Can I upgrade an existing line from standard to heavy-duty?

A: At the link level, yes - the geometry is interchangeable across the range. The track, the support steelwork and the drive position all survive an upgrade. The joints between old and new links and the two wear rates in a partly upgraded loop are what need planning.

Q7: Does the chain need to be greased?

A: No routine re-greasing is required under normal conditions, because the wheel bearings are sealed at assembly. In abrasive or high-temperature duty the seals should still be inspected on the maintenance schedule, since a damaged seal turns a sealed bearing into an open one.

Q8: What is the minimum curve radius?

A: R600 horizontal and R2500 vertical on the standard variant, R650 and R2800 on HH, and R700 and R3200 on HA. Where a horizontal curve coincides with a vertical bend, send the layout rather than the two radii, because the combined geometry is tighter than either figure alone.

Q9: How do I identify a chain that has no markings left?

A: Measure the pitch across several pitches and divide, measure the horizontal and vertical wheel diameters, and photograph a link square-on with a ruler in frame. Those three answers identify the variant in most cases.

Q10: Can the chain run through a curing oven?

A: Yes. The standard variant is rated to 200 °C, HH to 220 °C and HA to 250 °C, with a high-temperature bearing option above that. The track through the oven section needs its own expansion arrangement in addition to the correct chain variant.

Q11: Do you supply spare parts and attachments separately?

A: Yes. Individual links, wheel assemblies, attachment pins and hanger interfaces are supplied separately, so a single damaged link does not mean a new chain.

Q12: What surface treatments are available?

A: E-coating in black as standard, E-coating with zinc plating for humid environments, and hot-dip galvanizing for outdoor, plating and mist-exposed duty. The grade should be chosen for the worst station on the loop, not the average.

Q13: What information do you need for a quotation?

A: The variant or the measured pitch and wheel diameters, the I-beam section, the loop length and bend count, the heaviest load on one suspension point, the maximum temperature, and the attachment interface. A photograph of a link and of the track resolves most of the rest.

Q14: Is the chain supplied in one piece?

A: It is supplied in cut lengths or link sets matched to the installation sequence. Where the line can only be released for short windows, the chain is made up in the lengths each window can absorb and labelled by position in the loop.

Send us the link, the track and the load.
Give our engineers the measured pitch and wheel diameters, the I-beam section, the load on one suspension point and the highest temperature on the loop, and we will come back with the variant, the surface treatment and the quantity that line actually needs.

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