HTD Timing Belt Sprockets
Profile: HTD (High Torque Drive) curvilinear tooth
Pitches: 3M (3mm), 5M (5mm), 8M (8mm), 14M (14mm)
Mounting: Pilot bore, QD bushing, Taper Lock bushing
Materials: Aluminum (small sizes), steel, cast iron
Brands: Gates (PowerGrip), Continental/ContiTech (Blackhawk)
In Stock: Same-day shipping from Houston
HTD (High Torque Drive) sprockets are the most widely used industrial timing belt drive components worldwide. Their curvilinear (semicircular) tooth form meshes with HTD timing belts to create a positive, no-slip drive that delivers precise speed ratios and reliable power transmission. HTD sprockets are available in four standard pitches covering applications from light instrumentation to heavy industrial conveyors.
Texas Belting stocks HTD sprockets in all four pitches with a range of tooth counts, belt widths, and mounting options. We carry both Gates PowerGrip and Continental Blackhawk lines, so you can get matched belt-and-sprocket sets from a single source with confirmed profile compatibility.
HTD Sprockets by Pitch
| Pitch | Details |
|---|---|
| 3M | Pitch: 3mm. Load: Light. Typical tooth counts: 12 to 72. Belt widths: 6mm, 9mm, 15mm. Mount: Pilot bore or set screw. Use: Small instrumentation, office machines, printers, small OEM equipment. Smallest HTD pitch. Aluminum sprockets common at this size. |
| 5M | Pitch: 5mm. Load: Medium. Typical tooth counts: 14 to 72+. Belt widths: 9mm, 15mm, 25mm. Mount: Pilot bore, QD, or Taper Lock. Use: The most common industrial HTD pitch. Packaging, conveyors, general industrial drives, pumps. Steel or aluminum sprockets. |
| 8M | Pitch: 8mm. Load: Medium to heavy. Typical tooth counts: 18 to 112+. Belt widths: 20mm, 30mm, 50mm, 85mm. Mount: Pilot bore, QD, or Taper Lock. Use: Heavy conveyors, machine tools, large pumps, compressors. Steel or cast iron sprockets. Second most common industrial pitch. |
| 14M | Pitch: 14mm. Load: Heavy to very heavy. Typical tooth counts: 28 to 216+. Belt widths: 40mm, 55mm, 85mm, 115mm, 170mm. Mount: QD or Taper Lock. Use: Heavy-duty industrial drives, mining, large conveyors, crushers. Largest HTD pitch. Cast iron or steel sprockets. |
HTD vs. GT Sprockets
HTD and GT are both curvilinear tooth profiles available at the same pitch sizes (3M, 5M, 8M), which causes frequent confusion. The key differences:
| Feature | Details |
|---|---|
| HTD Tooth Shape | Fully semicircular. The original curvilinear design. Load is concentrated at the tooth root. |
| GT Tooth Shape | Modified curvilinear (Gates patented). Load is distributed more evenly across the tooth face. Results in higher load capacity at the same pitch. |
| Compatibility | Not interchangeable. An HTD 8M belt will not work correctly on a GT3 8M sprocket, and vice versa. The tooth shapes are different enough to cause premature wear and failure. |
| When to Use HTD | Replacing existing HTD drives. General industrial applications where HTD capacity is sufficient. Multi-brand sourcing (HTD is an open standard, not proprietary). |
| When to Use GT | New designs requiring maximum load capacity per tooth. Servo and precision applications. Gates-specified drives. Upgrading from HTD for more capacity at the same belt width. |
Mounting Options
| Mount Type | Details |
|---|---|
| Pilot Bore | Rough-bored hub, finish-machined to shaft size. Set screw and keyway. Common on 3M and 5M sprockets. Low cost. Not easy to swap between shaft sizes. |
| QD Bushing | Removable tapered bushing. Fast install/removal. One sprocket fits many shaft sizes. Standard on medium to large 5M, 8M, and 14M sprockets. Most common industrial mount in North America. |
| Taper Lock | Split tapered bushing with compression bolts. High concentricity. Common on European-standard equipment. Stainless steel option for food/pharma. Available on 5M, 8M, and 14M sprockets. |
HTD Sprocket Part Number Decoder
HTD sprocket part numbers encode the tooth count, pitch, and belt width. Formats vary slightly by manufacturer, but these examples cover the most common patterns.
| Example | What It Means |
|---|---|
| P24-5M-15 | 24 teeth, 5M pitch, 15mm belt width. Pilot bore. |
| P36-5M-25 | 36 teeth, 5M pitch, 25mm belt width. Pilot bore. |
| P28-8M-20 | 28 teeth, 8M pitch, 20mm belt width. Pilot bore. |
| P48-8M-50 | 48 teeth, 8M pitch, 50mm belt width. Pilot bore or QD (check listing). |
| P34-14M-55 | 34 teeth, 14M pitch, 55mm belt width. QD or Taper Lock mount. |
| P18-3M-9 | 18 teeth, 3M pitch, 9mm belt width. Pilot bore. Aluminum. |
The "P" prefix indicates pilot bore on many manufacturer lines, but conventions vary. Some list the pitch first (e.g., "5M-24-15"). Send us any part number and we will cross-reference it.
Sizing an HTD Sprocket
To order the correct HTD sprocket, you need four pieces of information:
1. Pitch. Must match the belt: 3M, 5M, 8M, or 14M.
2. Tooth count. Determines the pitch diameter and speed ratio. Each pitch has a minimum recommended tooth count (typically 12 for 3M, 14 for 5M, 18 for 8M, 28 for 14M). Fewer teeth than the minimum causes excessive belt wrap and accelerated wear.
3. Belt width. The sprocket must accommodate the belt width you are running. Standard sprockets are designed for specific belt width ranges (e.g., a "15" sprocket accepts up to 15mm wide belts).
4. Mounting and bore. Pilot bore (specify shaft diameter for machining), QD (specify bushing letter and bore), or Taper Lock (specify series and bore).
For complete guidance on tooth count selection, speed ratio calculations, and minimum pulley diameters, see our Sprocket Selection Guide.
Common Applications
| Application | Typical HTD Sprocket |
|---|---|
| Packaging machines | 5M or 8M. 20 to 48 teeth. Pilot bore or QD. Indexing and feed drives. |
| Conveyor systems | 5M or 8M. 24 to 72 teeth. QD mount for maintenance. Head and tail drives. |
| Pumps | 5M or 8M. 24 to 48 teeth. QD or Taper Lock. Positive displacement and centrifugal. |
| CNC/machine tools | 5M or 8M. Pilot bore. Spindle and axis drives where HTD capacity is sufficient. |
| Printing/converting | 5M. 18 to 36 teeth. Pilot bore. Registration and feed rollers. |
| Heavy conveyors/mining | 8M or 14M. 36 to 112+ teeth. QD or Taper Lock. Large pitch diameters, high torque. |
| Small OEM/instrumentation | 3M. 12 to 36 teeth. Pilot bore. Aluminum. Encoders, small actuators. |
Brands We Carry
| Brand | Products |
|---|---|
| Gates | PowerGrip HTD sprockets in 3M, 5M, 8M, and 14M. Pilot bore, QD, and Taper Lock. Industry standard for HTD drive components. |
| Continental | Blackhawk HTD sprockets. Strong 5M and 8M selection for industrial replacement. |
We cross-reference between Gates, Continental, Martin, and other sprocket manufacturers. Send us any part number and we will confirm the match.
Related Pages
Frequently Asked Questions
What does HTD stand for?
HTD stands for High Torque Drive. It refers to a curvilinear (semicircular) tooth profile designed for higher load capacity than the older trapezoidal (XL, L, H) profiles. HTD was developed to reduce tooth shear and improve load distribution in industrial timing belt drives.
Can I use an HTD sprocket with a GT belt?
No. HTD and GT tooth profiles are shaped differently even at the same pitch. HTD teeth are fully semicircular while GT teeth have a modified shape that distributes load differently. Running a GT belt on an HTD sprocket causes accelerated wear, noise, and drive failure. Always match the exact profile: HTD belts on HTD sprockets, GT belts on GT sprockets. See our Tooth Profiles guide for a visual comparison.
Which HTD pitch should I use?
5M is the default for most industrial applications. It handles moderate loads across packaging, conveyors, pumps, and general drives. Step up to 8M for higher torque or larger drives, and to 14M for heavy-duty, high-HP applications. Use 3M only for very light, precision applications like small instruments or encoders. Our Sprocket Selection Guide covers pitch selection criteria in detail.
What is the minimum number of teeth for an HTD sprocket?
Recommended minimums are: 12 teeth for 3M, 14 teeth for 5M, 18 teeth for 8M, and 28 teeth for 14M. Using fewer teeth than the minimum causes the belt to wrap too sharply around the sprocket, which accelerates tooth wear and reduces belt life. Higher tooth counts are gentler on the belt and allow higher operating speeds.
What mounting options are available for HTD sprockets?
Three main options: pilot bore (rough-bored hub, finish to your shaft size, set screw mount), QD bushing (removable tapered bushing, fast install/removal, fits multiple shaft sizes), and Taper Lock (split tapered bushing, high concentricity, stainless option for food/pharma). Pilot bore is most common on smaller 3M and 5M sprockets. QD and Taper Lock are standard on larger 5M, 8M, and 14M sprockets.
My belt says "8M" but I also see "8MGT" sprockets. Are they the same?
No. A belt marked "8M" or "HTD 8M" requires an HTD 8M sprocket. A belt marked "8MGT" or "GT3 8M" requires a GT3 8M sprocket. The tooth shapes are different and not interchangeable. If you are unsure, send us the full belt part number and we will confirm which sprocket profile you need.
Can I buy matched HTD belt and sprocket sets?
Yes. Tell us the pitch, tooth count, belt width, and required shaft bore sizes, and we will quote a complete drive package including HTD belt, sprockets, and bushings. Request a drive package quote.
Can Texas Belting cross-reference HTD sprocket part numbers?
Yes. We cross-reference between Gates (PowerGrip), Continental (Blackhawk), Martin, and other manufacturers. Send us the part number from your existing sprocket and we will confirm the equivalent in stock, or call 888-203-2358.
