GT Timing Belts (3MGT, 5MGT, 8MGT, 14MGT)

GT timing belts are Gates' refined curvilinear synchronous belts – a modified tooth geometry over HTD that delivers higher load capacity, reduced backlash and tighter registration on the same nominal metric pitches. Texas Belting stocks 1,100+ Gates GT belts in Houston, TX across 3MGT, 5MGT, 8MGT and 14MGT, in both PowerGrip GT and Poly Chain GT Carbon lines.

Shop GT belts by pitch

On this page: The GT lineup · GT vs HTD interchange · Poly Chain GT Carbon · Read a part number · Houston supplier · Common mistakes · FAQ

The GT lineup: pitches and generations

GT is a profile family, not a single belt. Gates has iterated the design through generations – GT2, GT3 and today's GT4 – while keeping the tooth geometry compatible within each pitch, so a newer-generation belt replaces an older one on the same sprockets. Our shelf follows Gates' current lineup: PowerGrip GT3 in the small 3MGT and 5MGT pitches, PowerGrip GT4 leading the 8MGT and 14MGT stock, alongside Poly Chain GT Carbon in 8MGT and 14MGT.

Gates also produces 2MGT for miniature drives; we stock from 3MGT up and can order 2MGT on request. Gates' published comparisons put GT-family capacity well above same-pitch HTD – GT3 literature claims roughly twice the capacity of an equivalent HTD drive, and GT4 adds up to 25 percent over GT3. Verify against the Gates drive manual for your specific belt.

If a drawing calls out GT2, order the same pitch and size in the current generation – the sprockets do not change. Where the drawing shows plain 8M or 14M, check the sprockets before assuming HTD: plenty of drives have been quietly upgraded to GT hardware over the years.

GT vs HTD: the interchange rules

This is the question that brings most people to GT belts: the drive has HTD sprockets, and the counter offers a GT belt – or the reverse. The rules come from Gates' own interchange documentation, and they are directional. A GT belt in an HTD sprocket is approved in the two big pitches as a replacement; an HTD belt in a GT sprocket is never approved at any pitch.

Interchange positions are based on manufacturer-published equivalents. Verify dimensions before ordering.

The full reasoning – tooth-form geometry, what "Replacement Only" means in practice, and how to identify which profile your sprockets are cut for – is on our HTD vs GT guide.

Poly Chain GT Carbon: the chain replacer

Poly Chain GT Carbon is Gates' polyurethane synchronous belt with carbon-fiber tension cords, built on the GT tooth form in 8MGT and 14MGT. It targets the drives where roller chain traditionally lived: high torque at low speed, wash-down and corrosive environments, and installations that should never need lubrication or re-tensioning. The polyurethane body shrugs off chemicals that attack rubber belts, and the carbon cords hold length under shock loads.

The critical caveat: Poly Chain belts run on Poly Chain sprockets. Do not mix Poly Chain belts with PowerGrip GT or HTD sprockets, or vice versa – capacity ratings and fit are published only for matched systems. If you are converting a roller-chain drive, we quote belt and sprockets as a set; see the Poly Chain GT Carbon page for the full line.

How to read a GT part number

Gates GT part numbers read pitch length, pitch code, width. A 1600-8MGT-30 is 1,600 mm around, 8 mm GT pitch, 30 mm wide – 200 teeth, since pitch length divided by pitch gives the tooth count. Poly Chain numbers put the pitch first (14MGT-1750-37 is a 14 mm pitch, 1,750 mm, 37 mm wide belt), so check which number is the length by dividing: in the 8 mm and 14 mm pitches, only the length divides evenly by the pitch.

• 1600-8MGT-30: 1,600 mm pitch length / 8 mm = 200 teeth; 30 mm wide.
• 14MGT-1750-37: 1,750 mm / 14 mm = 125 teeth; 37 mm wide.
• Width is capacity: within a pitch, going wider is how you add load rating without changing sprockets, as long as the sprocket face carries it.

GT timing belt supplier in Houston, TX

Texas Belting & Supply stocks its Gates GT inventory – PowerGrip GT3, GT4 and Poly Chain GT Carbon – in Houston, and most stocked sizes ship same day. We supply plants, OEMs and repair shops across the Texas Gulf Coast and ship nationwide, and we can pair any GT belt with matching sprockets and bushings from stock. For 2MGT, long lengths or full drive conversions, call (888) 203-2358 to confirm availability.

Common GT belt selection mistakes

• Putting an HTD belt on GT sprockets. It fits by eye and fails under load – the direction Gates never approves. Check what the sprockets are cut for.
• Treating "Replacement Only" as a design rating. An 8MGT belt in HTD sprockets is fine to run out a drive, but new drives should get GT sprockets to earn the full GT rating.
• Assuming small pitches interchange like the big ones. The 8 mm and 14 mm approvals do not extend to 5MGT (not recommended) or 3MGT (not rated).
• Mixing Poly Chain and PowerGrip components. Same tooth family, different systems – published ratings apply only to matched belt and sprockets.
• Confusing pitch-first and length-first part numbers. Divide by the pitch: in the 8 mm and 14 mm pitches only the length divides evenly – standard widths never do.
• Ignoring generation on precision drives. GT4 replaces GT3 on the same sprockets, but on registration-critical drives, re-check tension after a generation swap – the body compound changed (GT4 moved from neoprene to an EPDM elastomer).

When to call instead of browse

• You need 2MGT or a length or width outside our stocked range.
• You are converting roller chain or HTD to Poly Chain and want the drive engineered as a package.
• The sprocket markings are gone and you need the profile identified from a photo or a tooth tracing.

Call (888) 203-2358 or send us what you have – sprocket photos and tooth counts are usually enough.

Frequently asked questions

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Last updated: July 2026