Description
3V Belt Size Chart 16″-145″ 9.5x8mm ISO 4184 for Home Laundry Industrial
The smallest of the classical narrow V-belt sections, engineered to transmit 50–80% more power than a conventional V-belt of the same top width. 3/8 inch top width, 8 mm section height, chloroprene rubber body for genuine oil, heat, ozone and static resistance. The space-saving answer for compact drives.

What Is a 3V Belt
A narrow-profile V-belt built to deliver exceptional power in the tightest of spaces — the smallest of the 3V/5V/8V family.
The 3V belt is a wrapped narrow V-belt with a 3/8 inch (9.7 mm) top width and an 8 mm section height. It is the smallest section in the classical narrow V-belt range, and that size is the whole point: where a machine designer has almost no room for a drive but still needs to move real torque, the 3V is the section that gets specified. Its job is to deliver serious power transmission in a footprint where a classical section simply will not fit.
The capacity comes from the narrow profile itself. A deeper, narrower belt seats into the groove with more sidewall contact per millimetre of belt width, so it develops more grip at the same tension. The published figure is that a 3V transmits 50–80% more power than an ordinary V-belt of the same top width. For a machine designer, that difference is not an academic number — it is the reason a compact drive can stay compact and still move the load that used to require a much wider belt.
Our 3V belts are moulded rather than cut, so every belt of the same specification leaves production with an identical length. In a matched multi-belt drive that means every belt carries the same share of load from the first hour. No one belt runs tight and takes the punishment, no flank wears out early, and no unexpected break stops a production line. Because different production batches are moulded to the same length tolerance, a replacement ordered months later drops straight into the same drive without re-engineering the frame.
Every belt is manufactured to ISO 4184, the international standard covering dimensional tolerances and performance requirements for V-belts. When you specify our 3V belt, you are ordering a part that seats correctly in any ISO 4184-compliant 3V groove and runs to a known length tolerance.
Complete Technical Specifications
Verified under ISO 4184 test conditions. Supplied in matched lengths for multi-belt drives.
Materials & Construction
Three layers, each doing one job properly. Built on chloroprene rubber for genuine resistance to oil, heat, ozone and static.
Imported high-tenacity polyester cords give exceptional tensile strength with very low elongation under load, and are chemically bonded into the rubber body so they will not separate after millions of flex cycles.
The compression section is formulated from chloroprene rubber, giving the belt genuine cold and heat resistance, oil and chemical resistance, and anti-static performance for harsh plant environments.
A treated fabric is wrapped around the full belt to protect the sidewalls from abrasion and oil mist, while raising the friction the belt needs in the sheave groove.
Why Choose Our 3V Wrapped V-Belt
Every claim below is measurable on the drive, not just on a spec sheet.
At 3/8 inch top width and 8 mm height, the 3V lets you build a compact drive system, saving frame space and reducing the overall weight of the machine.
Transmits 50–80% more power than a conventional V-belt of the same top width. Small belt, full torque — the reason a 3V is specified for tight-frame machinery.
Polyester cords hold their length under maximum tension. Belts do not run slack after break-in, so re-tensioning stays rare and unplanned stops stay off the calendar.
In continuous running under rated load, measured belt wear stays below 2% even after 1,000 hours on the drive. Fewer changeouts, no production line halted for a belt swap.
Resistant to heat, oil and abrasion, the 3V runs safely and stably during high-speed operation and in harsh environments without cord damage or sidewall cracking.
The wrapped cover and narrow profile keep friction high in the groove. When a load spikes suddenly, the belt stays seated and torque keeps moving to the driven machine.
At 95%+ transmission efficiency, more motor output reaches the driven shaft. Over a belt’s service life that difference shows up on the energy bill.
Moulded to length under ISO 4184, so a replacement ordered six months later drops into the same drive without re-engineering the frame.
Set the tension correctly at installation and the belt runs for the duration of its service life with only routine visual inspection.
Fatigue resistance rated in the millions of cycles, with crack resistance and ozone resistance built into the compound for reliable indoor and outdoor service.
Industries & Equipment Served
The 3V is specified wherever the frame is tight, the load is real, and downtime is expensive.
Steel & Metallurgy
Drilling machines, sawing machines, plate shears, forming machines, conveyors, crushers, mixers, separators, feeders, belt conveyors, cutting equipment and full auxiliary systems. Continuous heavy load is the condition that separates a durable belt from one that fails early.
Construction & Building Materials
Milling-planing machines, mixers and other site equipment. Jobsite debris, dust and long run hours expose a weak belt fast; the 3V is built for all three.
Industrial Ventilation & HVAC
Air handling units, dust extraction fans, industrial ventilation and drying systems. Compact drives with continuous high-speed running — belt life becomes a direct maintenance cost.
Agricultural Machinery
Seed drills, rotary tillers, mowers, rice mills, micro-tillers, fertiliser spreaders, paddy de-huskers, grain grading screens, cleaning screens, ditch openers and pruning machines.
Mining & Aggregates
Crushing and conveying lines where shock loads arrive without warning. The wrapped jacket and stable cords keep the belt in service between scheduled changeouts rather than on an emergency call-out.
Auxiliary Equipment Across All Sectors
Air compressors, pumps, industrial fans, gear reducers, mixers, blowers, conveyors and pulverizers. If a machine needs to turn reliably in a tight frame, the 3V belt is on the bill of materials.

Reading the 3V Code & Matched Sets
Like all 3V/5V/8V belts, the 3V uses a simple code convention: 3V followed by a number that is the outside circumference in inches. So 3V1000 has an outside circumference of 100 inches — about 2540 mm. The number is not the pitch length; the pitch length is shorter by the profile offset, and that conversion is listed in the downloadable chart below.
The listing covers a wide range of fractional sizes too: 3V215, 3V235, 3V255, 3V265 and every half-inch step up to 3V775, 3V825 and 3V865, alongside the full inch steps from 3V170 through 3V2080. If the exact length you need is not in the standard listing, custom lengths are available — see the FAQ below.
For any drive using more than one belt, install a matched set. Because our belts are moulded to a consistent length, every belt in the set carries the same share of load. A common failure pattern is one new belt paired with several worn belts: the new belt runs tight, takes almost all the tension and fails in days. Replacing the full set is always the lower-cost choice over the life of the drive.
If you are unsure of the correct code, send us the centre distance, both sheave diameters and the service factor you want to apply. Our engineering team will return a recommended belt code, normally within one working day. MOQ 100 pcs | Delivery 15–20 days.

3V Size Chart & PDF Download
The table below groups the full (9N)3V belt range into practical length bands. The complete range runs from 3V170 to 3V2080, with the inch-step listing including fractional sizes such as 3V170, 3V260, 3V400, 3V600, 3V900 and 3V1300. Every size is available through the product options on this page. For the complete dimensional chart — outside circumference in inches, conversion to pitch length and millimetres, sheave groove dimensions per ISO 4184 and the full length-by-length listing.
| Outside Circ. (in) | Belt Code | Approx. Outside (mm) | Typical Application |
|---|---|---|---|
| 17 – 26 in | 3V170 to 3V260 | 432 – 660 mm | Compact blowers, fans, hand-held equipment |
| 26 – 40 in | 3V260 to 3V400 | 660 – 1016 mm | Compressors, pumps, small conveyors |
| 40 – 60 in | 3V400 to 3V600 | 1016 – 1524 mm | HVAC fans, mixers, press drives |
| 60 – 90 in | 3V600 to 3V900 | 1524 – 2286 mm | Conveyors, crusher auxiliaries, planers |
| 90 – 130 in | 3V900 to 3V1300 | 2286 – 3302 mm | Steel-plant auxiliaries, mills |
| 130 – 180 in | 3V1300 to 3V1800 | 3302 – 4572 mm | Long conveyors, aggregate plants |
| 180 – 208 in | 3V1800 to 3V2080 | 4572 – 5283 mm | Maximum-span compact-profile drives |
All 3V wrapped narrow V-belts are manufactured to the ISO 4184/RMA IP-22 standard for narrow V-belt drives, ensuring full dimensional interchangeability with equivalent-profile (9N)3V belts from other mainstream international manufacturers.
The 3V belt range covers 225 sizes from 3V-235 to 3V-2080. Sizes listed with prices on this page are in stock for quick ordering; the complete size list is available in the downloadable specification PDF.
📄Download the (9N) 3V belt specification and complete ISO 4184 size chart PDF
Installation & Maintenance
Correct Installation Procedure
- Loosen the driven-unit mounting bolts and reduce the centre distance before fitting the belt. Never lever a belt over a sheave rim — the forced bend will break tension cords at one point along the belt.
- Seat the belt in the grooves, then increase the centre distance gradually to apply tension.
- Tension to the specified value with a proper tension gauge. Too tight overloads the bearings; too loose causes slip, heat and rapid wear.
- Run the drive 15–30 minutes under light load so the belt beds into the grooves, then re-check and adjust tension once.
- Check sheave alignment with a straightedge. Misalignment wears one belt sidewall quickly and shortens belt life.
Maintenance Guidelines
- Inspect belts every 500 operating hours for glazing, cracking or exposed cords.
- Keep sheaves clean and free of oil, grease and embedded debris.
- Replace all belts in a matched set together — never replace one belt alone.
- Store spares in a cool, dry place away from direct sunlight and ozone sources such as electric motors.
Troubleshooting Guide
The belt cannot be tensioned
Possible causes: the centre-distance adjustment range is too small; the belt has stretched beyond recovery or the drive frame is undersized and overloaded; the belt length is wrong.
Remedies: re-design the drive with a larger adjustment range; re-calculate the drive data and resize the drive; select the correct 3V length.
The belt wears out too quickly
Possible causes: the belt has exceeded its service life and the compound has aged; the drive imposes excessive tension; poor installation causes misalignment, uneven wear or vibration.
Remedies: replace on a fixed schedule, correct the drive design, and align and seat the belt properly at installation.
The belt breaks after a short time
Possible causes: it was pried onto the sheave and cords were damaged; a foreign object entered the drive and snapped it; the driven system seized; severe shock loading or a load applied too suddenly.
Remedies: loosen the mounting bolts and reduce centre distance to fit the belt with no forced leverage; fit a guard to keep debris out; stop and clear the fault before restarting; re-design for the actual shock load and ramp loads up gradually.
Black powder is coming off the belt
Cause: on a new installation the sheave surface finish is too rough, so the belt rubs off fine black rubber dust.
Remedy: improve the sheave surface finish.
The belt slips
Possible causes: insufficient tension, worn or contaminated sheave grooves, or a drive ratio that no longer matches the requirement.
Remedies: adjust tension to the specified value with a tension gauge; inspect and replace worn or contaminated grooves; correct or replace the drive so the ratio matches.
Frequently Asked Questions
What is the minimum order quantity for 3V belts?
Our standard MOQ is 20 pieces per size. For mixed-length orders, recurring supply contracts or bonded warehouse programmes, contact our sales team for volume pricing and a flexible MOQ.
What is the delivery lead time?
Standard delivery is 15-20 days from order confirmation, depending on order volume and current production scheduling. Rush orders can be accommodated on request.
Do you support custom belt lengths?
Yes. We supply custom lengths outside the standard range, and we also manufacture banded (joined) V-belts for drives where multiple belts must run as a set.
How do I read the 3V belt code?
The number after 3V is the outside circumference in inches. So 3V670 is a 3V belt with a 67 inch outside circumference. 9N is the ISO designation for the same 3/8 inch narrow V-belt section.
What material is the 3V belt made from?
The body is a chloroprene rubber (CR) compound with a polyester tension cord and a wrapped fabric jacket for oil, heat and abrasion resistance.
Are your 3V belts ISO certified?
Our 3V belts are manufactured to the ISO 4184 standard for narrow V-belt drives and are dimensionally interchangeable with equivalent-profile 3V V-belts from other mainstream international manufacturers.
What temperature can the standard 3V belt handle?
The standard chloroprene rubber 3V belt works from about -40 °C to +90 °C. For higher temperatures, ask about special heat-resistant compounds.
How do I identify my current 3V belt?
The code is printed or embossed on the belt back, for example 3V670 for an outside circumference of 67 inches. If the marking has worn away, measure the outside circumference and top width and send both figures to us – we will identify the correct replacement.
Ready to Specify Your (9N)3V belt?
Send the belt code, quantity and required delivery date. We will confirm stock, issue a formal quote and ship within 15–20 days.
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