Open-End Timing Belts
Open-end timing belts are sold in continuous rolls rather than as pre-made endless loops. They can be cut and joined to any length, making them the solution when standard factory-molded belt lengths do not match your drive, when your machine requires a non-standard length, or when your application is linear motion where the belt does not form a continuous loop at all.
Open-end timing belts are manufactured in polyurethane (not neoprene) and are available with steel cord, aramid (Kevlar) cord, or fiberglass cord reinforcement across all major tooth profiles.
When to Use Open-End Timing Belts
Open-end belts solve specific problems that standard endless (factory-joined) timing belts cannot:
- Non-standard belt lengths. Standard endless timing belts are manufactured in fixed pitch lengths. If your drive requires a length that is not available as a stock belt, an open-end belt can be cut and joined to the exact pitch length you need.
- Linear motion systems. In linear actuators, gantry systems, and CNC positioning tables, the belt does not form a continuous loop. Both ends of the belt are anchored to a carriage, and the belt wraps around a drive pulley. Open-end belts are the only option for these applications.
- Long-span drives. Some conveyor or transport drives require belt lengths that exceed the longest available stock endless belt. Open-end belts can be cut to any length from rolls.
- Inventory reduction. Stocking one roll of open-end belt and cutting to length as needed reduces the number of individual belt SKUs your storeroom needs to carry.
- Machines with variable setup lengths. Equipment that is reconfigured for different product runs may need different belt lengths for each setup. Open-end belt cut from a roll handles this without stocking multiple endless belt sizes.
How Open-End Belts Are Joined
When an open-end belt needs to form a continuous loop (rather than anchoring both ends as in linear motion), the two ends must be joined. There are three common joining methods:
| Joining Method | How It Works | Strength | Best For |
|---|---|---|---|
| Metal splice clips | Interlocking metal clips press-fitted into the belt ends, joined with a connecting pin or wire. | 60% to 75% of belt's rated strength | Quick installation, field repair, applications where the belt can be periodically replaced. Most common method. |
| Welded (heat fused) | Belt ends are cut at a precise angle, heated, and pressed together to form a fused joint. | 80% to 90% of belt's rated strength | Higher-strength applications, cleaner joint profile, applications where splice clips would interfere with pulleys or guides. |
| Finger splice (molded) | Belt ends are cut into interlocking finger patterns and bonded. Provides the smoothest running joint. | 85% to 95% of belt's rated strength | Premium applications requiring maximum joint strength and smooth pulley engagement. Typically factory-made. |
Available Profiles and Pitches
| Profile | Pitch | Tooth Shape | Standard Widths | Cord Options |
|---|---|---|---|---|
| GT2 | 2 mm | Curvilinear (GT) | 6 mm, 9 mm | Steel, fiberglass |
| HTD 3M | 3 mm | Curvilinear | 6 mm to 15 mm | Steel, fiberglass, aramid |
| HTD 5M | 5 mm | Curvilinear | 9 mm to 25 mm | Steel, fiberglass, aramid |
| HTD 8M | 8 mm | Curvilinear | 15 mm to 85 mm | Steel, fiberglass, aramid |
| HTD 14M | 14 mm | Curvilinear | 40 mm to 115 mm | Steel, aramid |
| T2.5 | 2.5 mm | Metric trapezoidal | 4 mm to 10 mm | Steel, fiberglass |
| T5 | 5 mm | Metric trapezoidal | 10 mm to 25 mm | Steel, fiberglass, aramid |
| T10 | 10 mm | Metric trapezoidal | 16 mm to 50 mm | Steel, fiberglass, aramid |
| AT5 | 5 mm | Advanced trapezoidal | 10 mm to 32 mm | Steel, fiberglass, aramid |
| AT10 | 10 mm | Advanced trapezoidal | 16 mm to 50 mm | Steel, fiberglass, aramid |
| AT20 | 20 mm | Advanced trapezoidal | 25 mm to 100 mm | Steel, aramid |
| XL | 1/5" (5.08 mm) | Imperial trapezoidal | 1/4" to 1" | Fiberglass, steel (select) |
| L | 3/8" (9.525 mm) | Imperial trapezoidal | 1/2" to 2" | Fiberglass, steel (select) |
| H | 1/2" (12.7 mm) | Imperial trapezoidal | 3/4" to 3" | Fiberglass |
Open-end belts use the same tooth profiles and pitches as standard endless belts, so they run on the same pulleys. No pulley changes are needed when switching between open-end and endless belts of the same profile and pitch.
Steel Cord vs. Aramid vs. Fiberglass
| Cord Type | Elongation | Best For | Notes |
|---|---|---|---|
| Steel cord | Less than 0.03% | Linear motion, CNC, actuators, precision positioning, long spans | The default for most open-end applications. Near-zero stretch ensures consistent positioning over the full belt length. |
| Aramid (Kevlar) | Very low | High-speed drives, compact pulleys, applications needing flexibility with low stretch | More flexible than steel cord, allowing tighter bend radii. Lighter weight. Good for high-speed rotary drives. |
| Fiberglass | Low | General rotary drives, cost-sensitive applications | Most economical cord option. Adequate for standard rotary power transmission where precision positioning is not required. |
Open-End vs. Endless: How to Decide
| Factor | Open-End | Endless (Standard) |
|---|---|---|
| Length availability | Any length (cut from roll) | Fixed factory lengths only |
| Joint strength | 60% to 95% of belt rating (depends on splice method) | 100% (no joint, continuous molded) |
| Material | Polyurethane only | Neoprene, HNBR, or polyurethane |
| Cord options | Steel, aramid, fiberglass | Fiberglass (standard neoprene/HNBR), steel or aramid (urethane) |
| Linear motion use | Yes (standard for actuators and gantries) | Not practical (fixed loop length) |
| Cost per unit length | Varies. Bulk roll pricing can be lower per meter than individual endless belts. | Generally lower for standard stock lengths. Higher for non-stock lengths. |
| Inventory efficiency | One roll covers multiple belt lengths | Each length is a separate SKU |
| Best for | Non-standard lengths, linear motion, custom machines, inventory reduction | Standard rotary drives where a stock length is available |
Rule of thumb: If a stock endless belt in the correct profile, pitch, width, and length is readily available, it is the simplest and strongest option (no splice joint). If the length you need is not available, or if you are building a linear motion system, open-end is the way to go.
Common Applications for Open-End Timing Belts
| Application | Typical Profile | Cord | Why Open-End |
|---|---|---|---|
| Linear actuators | AT5, AT10, T5, T10, 5M, 8M | Steel | Belt ends anchor to carriage. Length set by travel distance. No loop needed. |
| CNC gantry systems | AT10, AT20, 8M, GT2/GT3 | Steel | Precision positioning. Belt length matches axis travel. Near-zero stretch. |
| 3D printers | GT2 (2 mm) | Steel or fiberglass | Custom axis lengths. Sold by the meter, cut to fit specific printer builds. |
| Pick-and-place machines | AT5, T5, 3M, 5M | Steel | Repeatable positioning. Belt length sized to machine layout. |
| Automated storage and retrieval | AT10, 8M, 14M | Steel | Long travel distances. Belt length determined by rack height or aisle length. |
| Packaging machine line changeover | 5M, 8M, T5 | Steel or aramid | Different product runs require different belt lengths. Cut from roll for each setup. |
| Custom conveyor drives | 5M, 8M, T10, AT10 | Aramid or fiberglass | Non-standard center distances. Joined into endless loop after cutting. |
| Food processing (FDA) | T5, T10, AT5, AT10, 5M | Stainless steel | FDA urethane with stainless steel cord for washdown and sanitation environments. |
Open-End Timing Belt Brands We Carry
- Continental (ContiTech): Synchroflex open-end polyurethane belts, steel and aramid cord, HTD and AT profiles
- Megadyne: Megalinear open-end polyurethane belts, steel cord, T and AT profiles
- BRECOflex / Breco: Precision open-end polyurethane belts, stainless steel cord, AT and T profiles, FDA options
- Bando: Select open-end polyurethane timing belts
- Gates: Poly Chain GT Carbon (endless only, but included here for reference as a polyurethane timing belt option)
We cross-reference open-end timing belts across all manufacturers. If you have a part number or need to match an existing belt, call 888-203-2358 and we will confirm the correct profile, width, cord type, and source.
Frequently Asked Questions
An open-end timing belt is a continuous length of toothed belt sold from a roll, rather than a factory-molded endless loop. It can be cut to any length and either joined into a loop using splice clips, welding, or finger splicing, or used with both ends anchored (as in linear motion systems). Open-end belts are manufactured in polyurethane with steel, aramid, or fiberglass tensile cords.
Standard neoprene and HNBR timing belts are manufactured as endless loops in a mold, and the molding process creates a seamless, continuous belt. This process does not lend itself to producing continuous rolls. Polyurethane can be extruded into continuous lengths, which is why open-end belts are exclusively polyurethane construction. The polyurethane material also facilitates heat-welded and clip-based splicing methods.
Yes. Open-end belts use the same tooth profiles and pitches as standard endless belts. A 5M open-end belt runs on the same 5M pulleys as a standard neoprene 5M belt. No pulley changes are needed.
Splice strength depends on the method used. Metal splice clips provide 60% to 75% of the belt's rated strength. Heat-welded joints achieve 80% to 90%. Precision finger splices reach 85% to 95%. A factory-molded endless belt has 100% rated strength with no splice. For applications where maximum load capacity is critical, an endless belt is preferred if a stock length is available.
Steel cord. It provides near-zero elongation (less than 0.03%), which is essential for consistent positioning accuracy in linear actuators, CNC gantries, and pick-and-place machines. Fiberglass and aramid cords have slightly more stretch and are better suited for standard rotary drives.
Yes. Open-end polyurethane timing belts are available with FDA 21 CFR compliant compounds and stainless steel tensile cord for food processing, pharmaceutical, and washdown applications. Specify FDA-grade when ordering. See our Food Grade Timing Belts page for more information on compliance requirements.
Yes. Texas Belting supplies open-end timing belts cut to your specified length from stock rolls. We also provide splicing and joining services for applications where the belt needs to form a loop. Call 888-203-2358 with your profile, width, cord type, and required length for a quote.
Related Pages
Need an Open-End Timing Belt?
Texas Belting supplies open-end polyurethane timing belts in all major profiles from Continental, Megadyne, BRECOflex, and Bando. We cut to length, provide splicing, and stock FDA-grade options. Tell us your profile, width, cord type, and length for a quote.
Request a Quote Call 888-203-2358