GT2 Timing Belt Sprockets: Gates PowerGrip GT2 and Poly Chain GT2
Profile: GT (Gates Tooth) modified curvilinear
Sprocket generation: GT2. Gates makes no GT3 or GT4 sprocket.
Belts they run: PowerGrip GT2, GT3 and GT4 belts on PowerGrip GT2 sprockets; Poly Chain GT Carbon belts on Poly Chain GT2 sprockets
Pitches: 2M (2mm), 3M (3mm), 5M (5mm), 8M (8mm), 14M (14mm)
Mounting: Pilot bore, minimum plain bore (MPB), QD bushing, Taper Lock bushing
Materials: Steel and cast iron; aluminum on small pitches
Brand: Gates (PowerGrip GT2 Sprockets, Poly Chain GT2 Sprockets)
In Stock: Same-day shipping from Houston
GT sprockets use the modified curvilinear tooth profile developed by Gates to deliver higher load capacity, lower noise, and longer belt life than standard HTD sprockets at the same pitch. The GT tooth shape distributes load across the tooth face rather than concentrating stress at the tooth root, so a GT drive can transmit more torque at the same belt width or use a narrower belt for the same load.
Texas Belting stocks Gates PowerGrip GT2 sprockets in 2M, 3M, 5M, 8M and 14M pitch, plus Poly Chain GT2 sprockets in 8M and 14M, and the matching GT timing belts, so you can source confirmed-compatible drive sets from a single supplier.
Which Sprocket Runs Which Belt
Use this table to pair a Gates GT-profile belt with the correct sprocket family. The belt generation printed on the belt does not change the sprocket you need.
| Pitch | Belt (current Gates product) | Sprocket to use | Part-number family |
|---|---|---|---|
| 2M | PowerGrip GT3 2MGT (also legacy GT2 2MR belts) | PowerGrip GT2 | 2MR-xxS-xx |
| 3M | PowerGrip GT3 3MGT (also legacy GT2 3MR belts) | PowerGrip GT2 | 3MR-xxS-xx |
| 5M | PowerGrip GT3 5MGT or Poly Chain GT Carbon 5MGT | PowerGrip GT / Poly Chain GT 5M sprocket (one sprocket serves both belts at this pitch) | Pxx-5MGT-xx-MPB |
| 8M | PowerGrip GT4 8MGT (replaced GT3 in 2020; legacy GT2 and GT3 belts fit the same) | PowerGrip GT2 | Pxx-8MGT-xx |
| 8M | Poly Chain GT Carbon 8MGT | Poly Chain GT2 | 8MX-xxS-xx |
| 14M | PowerGrip GT4 14MGT (replaced GT3 in 2020; legacy GT2 and GT3 belts fit the same) | PowerGrip GT2 | Pxx-14MGT-xx, Fxxx-14MGT-xx |
| 14M | Poly Chain GT Carbon 14MGT | Poly Chain GT2 | 14MX-xxS-xx |
GT Generations: Belts vs. Sprockets
| Generation | Belts | Sprockets |
|---|---|---|
| GT (original) | First Gates modified curvilinear belt. Superseded. | First-generation GT sprockets. Superseded by GT2; same tooth profile. |
| GT2 | Still made in Twin Power (double-sided), long-length, and made-to-order constructions. Standard single-sided stock belts moved to GT3. | Current. PowerGrip GT2 Sprockets and Poly Chain GT2 Sprockets are the sprocket lines Gates sells today, in every pitch. |
| GT3 | Current single-sided belt in 2M, 3M and 5M (2MGT, 3MGT, 5MGT). Same tooth profile as GT2 with improved construction. | No GT3 sprocket exists. GT3 belts run on GT2 sprockets. |
| GT4 | Current single-sided belt in 8M and 14M since 2020 (8MGT, 14MGT). Direct replacement for GT3 in those pitches; EPDM body, same fit. | No GT4 sprocket exists. GT4 belts run on GT2 sprockets. Gates has said the 8M and 14M sprockets may be relabeled GT4 in name only. |
GT2 Sprockets by Pitch
Tooth counts and belt widths below reflect what Texas Belting stocks in this collection.
| Pitch | Details |
|---|---|
| 2M (2MR) | Pitch: 2mm. Load: Very light. Tooth counts: 12 to 120. Belt widths: 6mm, 9mm. Mount: Pilot bore. Use: Miniature drives, small robotics, 3D printers, encoders, precision instruments. Smallest GT pitch. |
| 3M (3MR) | Pitch: 3mm. Load: Light. Tooth counts: 16 to 120. Belt widths: 6mm, 9mm, 15mm. Mount: Pilot bore. Use: Small OEM, office equipment, light automation, stepper motor drives. |
| 5M (5MGT) | Pitch: 5mm. Load: Medium. Tooth counts: 12 to 112. Belt widths: 9mm, 15mm, 25mm. Mount: Minimum plain bore (MPB), finish-bored to size. Use: Servo motors, packaging, precision positioning. One sprocket serves both PowerGrip GT3 5MGT and Poly Chain GT Carbon 5MGT belts. |
| 8M (8MGT) | Pitch: 8mm. Load: Heavy. Tooth counts: 22 to 192 (PowerGrip GT2), 22 to 224 (Poly Chain GT2 8MX). Belt widths: 12mm, 20mm, 30mm, 50mm, 85mm (PowerGrip); 12mm, 21mm, 36mm, 62mm (Poly Chain). Mount: Pilot bore, QD, or Taper Lock. Use: High-torque industrial drives, conveyors, machine tools, heavy packaging. |
| 14M (14MGT) | Pitch: 14mm. Load: Very heavy. Tooth counts: 28 to 224 (PowerGrip GT2), 28 to 224 (Poly Chain GT2 14MX). Belt widths: 40mm, 55mm, 85mm, 115mm, 170mm (PowerGrip); 20mm, 37mm, 68mm, 90mm, 125mm (Poly Chain). Mount: QD or Taper Lock. Use: Large conveyors, crushers, mixers, high-horsepower drives replacing roller chain. |
GT vs. HTD: Key Differences
GT and HTD sprockets share the same pitch sizes (3M, 5M, 8M, 14M) but use different tooth shapes. This is the most common source of profile confusion in timing belt drives.
| Feature | Details |
|---|---|
| GT Tooth | Modified curvilinear (Gates). Load distributed across the full tooth face. Higher capacity per tooth than HTD. |
| HTD Tooth | Fully semicircular. Load concentrated at the tooth root. Lower capacity per tooth than GT at the same pitch. |
| Load Capacity | GT carries substantially more load than HTD at the same pitch and belt width, so a GT drive can use a narrower belt for the same application. Use the Gates drive design manual for the rated horsepower of a specific belt and sprocket combination. |
| Noise | GT runs quieter than HTD due to better tooth engagement geometry. |
| Compatibility | Not interchangeable. GT belts require GT sprockets. HTD belts require HTD sprockets. Mixing causes premature failure. |
| Availability | GT is a Gates proprietary profile. HTD is an open standard available from multiple manufacturers. GT sprockets are sourced through Gates or authorized distributors. |
Mounting Options
| Mount Type | Details |
|---|---|
| Pilot Bore | Rough-bored hub, finish-machined to shaft size with set screw and keyway. Standard on 2MR and 3MR sprockets. Low cost. |
| Minimum Plain Bore (MPB) | Gates' pilot-bore designation on 5MGT sprockets (the "-MPB" suffix). Bored to your shaft size before shipment on request. |
| QD Bushing | Removable tapered bushing. Fast install and removal. One sprocket fits many shaft sizes. A suffix such as "-SK", "-E" or "-F" on a 14MGT part number is the QD bushing size it takes. |
| Taper Lock | Split tapered bushing. High concentricity and torque capacity. A numeric suffix such as "-3020" is the Taper Lock bushing number. |
GT Sprocket Part Number Decoder
Gates uses two numbering styles for GT-profile sprockets. Small pitches and Poly Chain sprockets lead with the pitch and a series letter; 5M, 8M and 14M PowerGrip GT2 sprockets lead with a "P" and the tooth count. Every example below is a GT2 sprocket, which is what the Gates catalog lists it as.
| Example | What It Means |
|---|---|
| 2MR-120S-09 | PowerGrip GT2 sprocket, 2mm pitch, 120 teeth, 9mm belt width. Pilot bore. |
| 3MR-24S-09 | PowerGrip GT2 sprocket, 3mm pitch, 24 teeth, 9mm belt width. Pilot bore. This exact part is listed on gates.com under PowerGrip GT2 Sprockets; it is not a "GT3" sprocket. |
| P45-5MGT-15-MPB | PowerGrip GT / Poly Chain GT 5M sprocket, 45 teeth, 15mm belt width, minimum plain bore. Runs GT3 5MGT and Poly Chain GT Carbon 5MGT belts. |
| P24-8MGT-20 | PowerGrip GT2 sprocket, 8mm pitch, 24 teeth, 20mm belt width. Runs PowerGrip GT4 8MGT belts (and legacy GT2/GT3). |
| P30-14MGT-115 | PowerGrip GT2 sprocket, 14mm pitch, 30 teeth, 115mm belt width. Runs PowerGrip GT4 14MGT belts (and legacy GT2/GT3). |
| 8MX-112S-36 | Poly Chain GT2 sprocket, 8mm pitch, 112 teeth, 36mm belt width. For Poly Chain GT Carbon belts only. |
| 14MX-56S-68 | Poly Chain GT2 sprocket, 14mm pitch, 56 teeth, 68mm belt width. For Poly Chain GT Carbon belts only. |
"MR" marks the PowerGrip GT2 small-pitch series (2MR, 3MR). "MX" marks the Poly Chain GT2 series (8MX, 14MX). "MGT" in a P-prefix number is the pitch and profile (5MGT, 8MGT, 14MGT). If you have a part number you cannot decode, send it to us and we will identify the sprocket.
Why GT for Precision Drives
GT sprockets are the preferred choice over HTD for applications requiring precise positioning, low backlash, and high repeatability. The modified tooth shape provides tighter mesh between belt and sprocket, which reduces angular backlash (the amount the driven shaft can rotate when the driving shaft is held fixed). This matters in servo motor drives, CNC axes, pick-and-place machines, and any application where positional accuracy is critical.
GT drives also run quieter than HTD at the same speed, which is important in printing, medical equipment, and laboratory instrumentation where noise levels matter.
Common Applications
| Application | Typical GT Sprocket |
|---|---|
| Servo motor drives | 3MR or 5MGT PowerGrip GT2. Pilot bore. Tight backlash and high repeatability. |
| Packaging machines | 5MGT or 8MGT PowerGrip GT2. Pilot bore or QD. Indexing, registration, and feed drives. |
| Printing/converting | 5MGT PowerGrip GT2. Pilot bore. Precise web control and roller registration. |
| CNC machine tools | 5MGT or 8MGT PowerGrip GT2. Spindle drives and axis motion where precision and torque both matter. |
| Robotics/automation | 2MR or 3MR PowerGrip GT2. Pilot bore. Small actuators, pick-and-place, gantry systems. |
| 3D printers | 2MR PowerGrip GT2. X/Y axis drives. Very light loads, high precision. |
| Heavy conveyors and roller-chain replacement | 8MGT or 14MGT PowerGrip GT2 with GT4 belts, or 8MX/14MX Poly Chain GT2 with Poly Chain GT Carbon belts. QD or Taper Lock. |
| Medical equipment | 2MR or 3MR PowerGrip GT2. Low noise, high precision. Lab automation, imaging, dispensing. |
Brands We Carry
| Brand | Products |
|---|---|
| Gates | PowerGrip GT2 sprockets in 2MR, 3MR, 5MGT, 8MGT and 14MGT, and Poly Chain GT2 sprockets in 8MX and 14MX including stainless. Pilot bore, MPB, QD, and Taper Lock. The GT profile is a Gates proprietary design, and Gates is the source for GT sprockets. |
Since GT is a Gates proprietary profile, cross-referencing is limited to Gates part numbers. If you have a GT sprocket part number from any source, send it to us and we will confirm availability.
Related Pages
Frequently Asked Questions
Do you carry GT3 or GT4 sprockets?
There is no such product. Gates has only ever made one generation of GT sprocket, sold as PowerGrip GT2 Sprockets (and Poly Chain GT2 Sprockets for Poly Chain belts). GT3 and GT4 are belt generations, and they run on GT2 sprockets. Every sprocket in this collection is the correct sprocket for a GT3 or GT4 belt of the same pitch. If a drawing or catalog specifies a "GT3 sprocket", order the PowerGrip GT2 sprocket with the same pitch, tooth count, and belt width.
Why are the sprockets GT2 when the belts are GT3 or GT4?
Gates numbers belts and sprockets separately. Belt generations changed the belt's construction (cords, rubber compound, tooth jacket) while keeping the same tooth profile, so each new belt still fits the existing sprocket. The sprocket line stayed at GT2 because nothing about it needed to change. Gates' own guidance is that PowerGrip GT3 belts are used in PowerGrip GT2 sprockets, and its 2020 GT4 launch FAQ states GT4 belts are compatible in fit, form, and function with the GT3 belts they replaced.
Do I need new sprockets to switch from GT3 to GT4 belts?
No. PowerGrip GT4 8MGT and 14MGT belts are a direct drop-in for the GT3 belts they replaced, with the same part numbers, and run on the same PowerGrip GT2 sprockets. Install the GT4 belt, tension to the Gates specification, and the drive is done.
What does GT stand for on a timing belt sprocket?
GT stands for Gates Tooth. It is a modified curvilinear tooth profile developed by Gates. The GT design distributes load more evenly across the tooth face than the standard HTD semicircular profile, resulting in higher load capacity, lower noise, and longer belt life at the same pitch size.
Can I use a GT sprocket with an HTD belt?
No. GT and HTD have different tooth shapes despite sharing the same pitch sizes (3M, 5M, 8M, 14M). Running an HTD belt on a GT sprocket causes accelerated tooth wear, noise, and eventual drive failure. Always match the exact profile: GT belts on GT sprockets, HTD belts on HTD sprockets. Check the belt marking carefully. See our Tooth Profiles guide for a visual comparison.
Can I run a Poly Chain GT Carbon belt on a PowerGrip GT2 sprocket?
Not at 8M or 14M. Poly Chain GT Carbon 8MGT and 14MGT belts require Poly Chain GT2 sprockets (8MX, 14MX). The one exception is 5M, where Gates makes a single PowerGrip GT / Poly Chain GT 5MGT sprocket that serves both belt families.
Why choose GT over HTD?
GT carries substantially more load than HTD at the same pitch and belt width, runs quieter, and provides tighter tooth engagement for lower backlash, which matters in servo, CNC, and precision positioning applications. The trade-off is that GT is a Gates proprietary profile with more limited sourcing options than the open-standard HTD.
What does 8MGT mean on a belt or sprocket?
8MGT means an 8mm pitch GT-profile belt or sprocket. The "8M" is the pitch and the "GT" means the Gates modified curvilinear tooth profile rather than the standard HTD semicircular profile. Today an 8MGT PowerGrip belt is a GT4 belt and an 8MGT PowerGrip sprocket is a GT2 sprocket; they are made for each other. An 8MGT sprocket is not interchangeable with a standard HTD 8M sprocket.
Are GT sprockets available with QD or Taper Lock mounting?
Yes. 8MGT and 14MGT PowerGrip GT2 sprockets and 8MX and 14MX Poly Chain GT2 sprockets are available with QD bushing and Taper Lock mounting. 2MR, 3MR and 5MGT sprockets use pilot bore or minimum plain bore. The mounting type is specified in the sprocket part number or product listing.
Can I buy matched GT belt and sprocket sets?
Yes. Tell us the pitch, tooth count, belt width, and shaft bore sizes, and we will quote a complete drive package including GT belt, GT2 sprockets, and bushings. Request a drive package quote or call (888) 203-2358.
