8B Series Cast Iron QD Pulleys | 8-Groove A/B V-Belt Sheaves
8B series pulleys are manufactured for A, AX, AA, 4L, B, BX, BB, and 5L v-belts, ranging from 5.75″ to 38.35″ in diameter. Depending on the pulley size, they are made to use with SD, SK, SF, or E QD bushings, which we also stock. The main benefit of using a QD (quick detachable) pulley is that if the bushing (hub) breaks, you don’t have to replace the whole assembly, or if just the pulley gets worn out, the same principle applies. The other significant benefit is that there is a broader range of bore options with QD pulleys than with the “fixed-bore” style.
8B Series Cast Iron QD Pulleys (8-Groove A/B V-Belt Sheaves)
Our 8B series eight-groove QD (Quick Detachable) bushed pulleys are high-performance power transmission sheaves built for heavy-duty industrial drives. Engineered to accommodate both A (4L) and B (5L) classical V-belts—as well as AX, BX, AA, and BB profiles—this series features outside diameters ranging from 5.75″ to 38.35″. Depending on the pulley size, they utilize standard SK, SF, E, or F QD bushings for efficient torque transmission and easy shaft mounting.

Key Features & Engineering Advantages
- High-Strength Construction: Precision machined from Grade 35 high-tensile cast iron to handle severe operational loads and reduce wear.
- Corrosion Protection: Treated with a phosphate conversion coating and finished with protective paint for long-lasting corrosion resistance in tough environments.
- Factory Dynamic Balance: Dynamically balanced at the factory to guarantee smooth, low-vibration machinery operation and prolong bearing life.
- Flexible QD Bushing Design: Quick Detachable bushings provide a secure shaft grip with versatile bore size options. Individual component replacement helps minimize long-term maintenance costs and downtime.
8B QD Pulleys Dimensional Specifications
| Size | Bushing Type | Pulley Type | Pitch Diameter (5L/B) | Pitch Diameter (4L/A) | Outside Diameter | (E) | (F) | (L) | (M) | Pulley Weight (LBS) |
|---|---|---|---|---|---|---|---|---|---|---|
| 8B54SK | SK | A | 5.4″ | 5.0″ | 5.75″ | 1-1/32″ | 6-1/4″ | 1-15/16″ | 3-9/32″ | 15.0 |
| 8B56SK | SK | A | 5.6″ | 5.2″ | 5.95″ | 1-1/32″ | 6-1/4″ | 1-15/16″ | 3-9/32″ | 16.0 |
| 8B60SF | SF | A | 6.0″ | 5.6″ | 6.35″ | 31/32″ | 6-1/4″ | 2-1/16″ | 3-7/32″ | 20.0 |
| 8B62SF | SF | A | 6.4″ | 6.0″ | 6.75″ | 31/32″ | 6-1/4″ | 2-1/16″ | 3-7/32″ | 23.0 |
| 8B68SF | SF | A | 6.8″ | 6.4″ | 7.15″ | 31/32″ | 6-1/4″ | 2-1/16″ | 3-7/32″ | 25.0 |
| 8B74SF | SF | A | 7.4″ | 7.0″ | 7.75″ | 31/32″ | 6-1/4″ | 2-1/16″ | 3-7/32″ | 28.0 |
| 8B86E | E | A | 8.6″ | 8.2″ | 8.95″ | 1-7/32″ | 6-1/4″ | 2-3/4″ | 2-9/32″ | 40.0 |
| 8B94E | E | A | 9.4″ | 9.0″ | 9.75″ | 1-7/32″ | 6-1/4″ | 2-3/4″ | 2-9/32″ | 43.0 |
| 8B110E | E | A | 11.0″ | 10.6″ | 11.35″ | 1-7/32″ | 6-1/4″ | 2-3/4″ | 2-9/32″ | 49.0 |
| 8B124E | E | A | 12.4″ | 12.0″ | 12.75″ | 1-7/32″ | 6-1/4″ | 2-3/4″ | 2-9/32″ | 56.0 |
| 8B154E | E | A | 15.4″ | 15.0″ | 15.75″ | 1-7/32″ | 6-1/4″ | 2-3/4″ | 2-9/32″ | 69.0 |
| 8B184F | F | A | 18.4″ | 18.0″ | 18.75″ | 7/32″ | 6-1/4″ | 3-3/4″ | 2-9/32″ | 91.0 |
| 8B200F | F | A | 20.0″ | 19.6″ | 20.35″ | 7/32″ | 6-1/4″ | 3-3/4″ | 2-9/32″ | 98.0 |
| 8B250F | F | A | 25.0″ | 24.6″ | 25.35″ | 7/32″ | 6-1/4″ | 3-3/4″ | 2-9/32″ | 121.0 |
| 8B300F | F | A | 30.0″ | 29.6″ | 30.35″ | 7/32″ | 6-1/4″ | 3-3/4″ | 2-9/32″ | 148.0 |
| 8B380F | F | A | 38.0″ | 37.6″ | 38.35″ | 7/32″ | 6-1/4″ | 3-3/4″ | 2-9/32″ | 194.0 |
Standard QD Bushing Mounting & Dismounting Guidelines
Mounting Procedure:
- Clean the tapered cone surfaces of both the bushing and the pulley hub to ensure they are free of dirt, grease, and metal burrs.
- Align the unthreaded clearance holes of the pulley with the threaded pull-up holes of the QD bushing.
- Insert cap screws with lock washers through the clearance holes and thread them finger-tight into the bushing.
- Slide the combined assembly onto the shaft and position it for precise drive alignment.
- Progressively tighten the cap screws in an alternating pattern to the specified torque. Maintain an even gap of 1/8″ to 1/4″ between the bushing flange and pulley hub to ensure maximum mechanical grip.
- Finally, tighten the set screw over the keyway to secure the key in position.
Note: Never apply lubricants or anti-seize compounds to the tapered surfaces or bolt threads, as this will lead to over-tightening and hub failure. Fill any remaining flange gaps after mounting to prevent dirt accumulation.
Dismounting Procedure:
- Loosen the set screw over the keyway and remove the main cap screws.
- Thread the cap screws into the threaded jacking-screw holes in the pulley hub.
- Tighten the screws evenly in an alternating pattern against the QD bushing flange until the tapered fit releases.
- Slide the loose assembly safely off the shaft.
Manufacturing Standards & OEM Capabilities
We manufacture all 8B series pulleys in strict compliance with ANSI/RMA industrial standards. We maintain an extensive inventory of standard 8B sheaves and matching SK, SF, E, and F QD bushings for fast order fulfillment. Custom bore configurations and OEM production based on technical drawings are available upon request.
Model Technical FAQs
Q: Which belt profiles can you run with 8B series pulleys?
A: You can run 8B series pulleys with 8-groove A, AX, AA, 4L, B, BX, BB, and 5L V-belts.
Q: Which bushing types do 8B series QD pulleys require?
A: Depending on the outer diameter and model size, 8B series pulleys require standard SK, SF, E, or F QD bushings for shaft mounting.
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How to choose power transmissions parts and industrial products which meet our requirement
| Chains | Sprockets | Pulleys | Timing belt Pulley | V-belt Pulley |
| Sheaves | Coupings | Bush &Hub | Gear& Rack | V-Belt |
| Locking Assembly | Pulley | Gearbox | Reducer | Shaft Collar |
| Rod End Bearing | Clevis | PTO | Chain Guide | Belt Guide |
| Rubber Buffer | Chain Tensioner | PTO Drive Shafts | Universal Joints | Roller Chains |
| Conveyor Chains | V-Belts | Worm Gearbox | Helical Gear | Worm |
| Agricultural Chain | CNC Proces Parts | Casting | Stamping | |
| Powder Metallurgy | CNC Proces Parts | Casting | Stamping |
What Products Do you sell ?
We are a group of factories, give customer one stop solution of power transmission and industrial products. We are in the position to supply wide range of products, including chains, sprockets, v-belt and v-belt pulleys, timing belt and timing belt pulleys, gears, speed reducers, motors, racks, couplings, and many other parts, like locking assembly, taper bushing, Chain guide, shaft collar, torque limiter, cam clutch, universal joint, motor base and motor slide, rod end, clevis, rubber mount, etc. We make special parts according to drawings and/or samples.
How to choose a gearbox which meets our requirement?
You can refer to our catalogue to choose the gearbox or we can help to choose when you provide
the technical information of required output torque, output speed and motor parameter etc.
What information shall we give before placing a purchase order?
a) Type of the gearbox, ratio, input and output type, input flange, mounting position, and motor informationetc.
b) Housing color.
c) Purchase quantity.
d) Other special requirements.
What industries are your gearboxes being used?
Our gearboxes are widely used in the areas of textile, food processing, beverage, chemical industry,
escalator,automatic storage equipment, metallurgy, tabacco, environmental protection, logistics and etc.
What is the producing process?
Production process including raw material cutting, machine processing, grinding, accessories cleaning, assemble, cleaning, stoving, oil coating, cover pressing, testing, package.
How to control the products quality?
Combining advanced equipment and strict management, we provide high standard and quality bearings for our customers all over the world.
What is the transportation?
-If small quantity , we Suggest to send by express, such as DHL,UPS, TNT FEDEX. If large amount, by air or sea shipping.
Can we design packaging?
-Yes. Default is regular packing, and we can make customer's own packing.
Can you provide OEM service?
-Yes, we work on OEM orders. Which means size, quantity, design, packing solution, etc will depend on your requests; and your logo will be customized on our products.
Can you give me discount on Power Transmissions Parts and Industrial parts?
-Yes, of course. Pls. send me your Email, you'll get more
Q: Are You a trading company or a manufacturer?
A: We Are the factory and have our Own trading company
Q: How Can I get an offer?
A: please send US quotation information: drawings, materials, weight, quantity and requirements, we can accept PDF, ISGS, DWG, STEP file format. If you don't have the drawings, please send us the samples, we can also quote you according to your samples.
Q: What is your minimum order size?
A: it is usually 100 pieces, but a low quantity is acceptable under some special circumstances.
Q: Do you provide samples? Is it free or extra?
A: Yes, we can provide samples free of charge, but we don't pay the freight.
Q: What is the lead time for mass production?
A: honestly, it depends on the number of orders. Normally, if you don't need the tools, deposit them after 30 days or so.
Q: What if the parts don't Work?
A: we can guarantee the quality, but if it happens, please contact us immediately, take some photos, we will check the problem and solve it as soon as possible.
Q: What are your terms of payment?
A: payment is less than US $1000,100% in advance. Payment: $1000,50% wire transfer in advance, balance before shipment,Other Terms of payment are negotiable







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