Open-End Timing Belts
Open-end timing belts (also called continuous roll, linear belt, or endless roll stock) are sold in bulk roll form and cut to the exact length your application requires. Unlike standard closed-loop timing belts that come in fixed circumference lengths, open-end belts give you the freedom to specify any length for linear motion systems, custom center distance drives, long conveyor runs, and applications where standard belt lengths are not available.
Open-end timing belts are manufactured almost exclusively from polyurethane with steel wire or Kevlar (aramid) tensile cords. The polyurethane body provides excellent chemical resistance, abrasion resistance, and low particulate generation. Once cut to length, open-end belts are joined into a loop using mechanical connectors (finger splices, pin connectors) or heat welding. Texas Belting stocks open-end timing belt roll stock in all major profiles for same-day shipping from Houston.
Body material: Polyurethane (thermoplastic PU)
Tensile cords: Steel wire (standard, near-zero stretch) or Kevlar/aramid (high flex life)
Sold as: Continuous roll stock, by the meter or foot
Joining methods: Mechanical finger splice, pin connector, or heat welding
Profiles available: T2.5, T5, T10, AT3, AT5, AT8, AT10, AT15, AT20, MXL, XL, L, H, HTD 3M/5M/8M, GT2/GT3
FDA/food contact: Available in FDA-compliant grades
Why Choose Open-End Over Closed-Loop?
Standard closed-loop timing belts come in fixed lengths determined by the manufacturer. Open-end belts solve problems that closed-loop belts cannot.
| Situation | Closed-Loop | Open-End |
|---|---|---|
| Standard center distance | Ideal. Choose from catalog lengths. | Not needed unless no catalog length fits. |
| Non-standard center distance | May not have exact length available. | Cut to any length. Solves the problem. |
| Linear motion / gantry | Not applicable (belt is not a loop). | Standard format. Belt runs in a straight line. |
| Very long belt lengths | Large closed-loops may not be cataloged. | Any length from roll stock. |
| Custom conveyor runs | Limited to available loop sizes. | Cut to match conveyor length exactly. |
| Replacement speed | Must stock exact length or wait for order. | Cut from roll stock on site for fast replacement. |
Open-End Profiles and Pitches Available
Open-end timing belts are available in most standard metric and imperial profiles. The T-profile and AT-profile families are the most widely available in open-end form because the European T/AT system was designed around polyurethane construction from the start.
| Profile Family | Pitches in Open-End | Common Widths | Primary Use |
|---|---|---|---|
| T-Profile | T2.5, T5, T10 | 6 to 100mm | European linear motion, custom drives, OEM replacement |
| AT-Profile | AT3, AT5, AT8, AT10, AT15, AT20 | 6 to 150mm | Heavy linear motion, high-precision positioning, gantry systems |
| HTD (curvilinear) | 3M, 5M, 8M | 6 to 50mm | Custom rotary drives, non-standard center distances |
| ANSI Trapezoidal | MXL, XL, L, H | 1/4" to 2" | Custom replacement for imperial drives, linear motion |
| GT (Gates Tooth) | GT2 (2mm), GT3 (3mm, 5mm, 8mm) | 6 to 25mm | 3D printers, hobby CNC, precision linear motion |
Not all pitches and widths are stocked in open-end form. Common sizes ship same day. Less common combinations may require 3 to 7 business days. Call 888-203-2358 to confirm availability for your specific profile, pitch, and width.
Steel Cord vs. Kevlar Cord for Open-End Belts
Open-end timing belts are reinforced with either steel wire or Kevlar (aramid) tensile cords. The cord type determines the belt's stretch, flex life, and suitability for different drive types.
| Property | Steel Wire Cord | Kevlar (Aramid) Cord |
|---|---|---|
| Elongation under load | 0.02% (near-zero stretch) | 0.3 to 0.5% (low stretch) |
| Best for | Linear motion, precision positioning, indexing | Rotary drives with small pulleys, high flex life needed |
| Minimum pulley size | Larger (steel is stiffer) | Smaller (Kevlar flexes tighter) |
| Fatigue life around small pulleys | Lower (steel can fatigue with repeated tight bending) | Higher (Kevlar resists flex fatigue) |
| Conductivity | Conductive | Non-conductive |
| Availability | Standard (most common) | Available, less common in some profiles |
Rule of thumb: Steel cord is the default for linear motion and any application where positional accuracy matters. Kevlar cord is preferred for rotary drives where the belt wraps around small pulleys and flex life is the priority. For more detail, see Urethane Timing Belts.
How Open-End Belts Are Joined
Once cut to length, open-end timing belts must be joined into a loop (for rotary drives) or attached to end fittings (for linear motion). There are three common joining methods.
Mechanical Finger Splice
The belt ends are cut with interlocking finger profiles that mesh together and are secured with a pin or clip. This is the fastest field-installable method and requires no special tools. Finger splices are suitable for moderate-load rotary drives and many linear motion applications. The joint is slightly thicker than the belt body and may produce a small bump as it passes over the pulley.
Pin Connector / Lacing
Metal or plastic pins are inserted through holes drilled in the belt ends. This method is simple and fast but creates a visible joint. It is used primarily for low-load and low-speed applications or for temporary installations.
Heat Welding (Thermal Splice)
The belt ends are butt-welded using a hot plate or hot air to fuse the polyurethane. A properly welded joint is nearly as strong as the belt body and produces a smooth, low-profile connection. Heat welding requires specialized equipment and is typically done in-shop rather than in the field. This is the preferred method for high-load and high-speed applications where joint strength and smoothness are critical.
Common Open-End Timing Belt Applications
| Application | Why Open-End | Typical Profile |
|---|---|---|
| Linear motion and gantry systems | Belt runs in a straight line. Steel cord for near-zero stretch positioning. | T5, T10, AT5, AT10, GT2 |
| CNC routers and laser cutters | Custom gantry length. Steel cord for repeatable axis positioning. | T10, AT10, AT20 |
| 3D printers (motion axes) | GT2 open-end cut to exact printer frame size. | GT2 (2mm) |
| Custom conveyor drives | Non-standard conveyor length. Cut belt to match exactly. | T5, T10, AT10, 8M |
| Pick-and-place and palletizing | Long stroke linear motion with heavy carriage loads. | T10, AT10, AT15 |
| Non-standard center distance drives | No catalog closed-loop length available. Cut open-end and join. | Any profile |
| Waterjet and plasma tables | Heavy gantry, long travel, custom table dimensions. | T10, AT10, AT20 |
| Food processing equipment | FDA-compliant urethane. Custom lengths for food conveyor systems. | T5, T10, AT10 |
For application-specific guidance, see Timing Belts for Linear Motion, Timing Belts for Packaging, and Timing Belts for Food Processing.
Open-End Timing Belt Brands We Carry
Texas Belting stocks and sources open-end timing belt roll stock from the following manufacturers.
| Brand | Open-End Products | Notes |
|---|---|---|
| Gates | PowerGrip urethane open-end (limited profiles) | Smaller open-end range. Stronger in closed-loop neoprene. |
| Continental / ContiTech | Synchroflex open-end T, AT profiles | Industry leader in European T/AT open-end urethane |
| Bando | Bando Bancollan open-end | Japanese manufacturing, precision urethane |
| Diesel Belting | Diesel urethane open-end | Cost-effective open-end option for standard profiles |
| Megadyne | Megalinear open-end T, AT, HTD, GT | Largest open-end range. Specialist in urethane roll stock. FDA grades. |
Megadyne and Continental carry the widest selection of open-end profiles and widths. Call 888-203-2358 with your profile, pitch, width, and length requirements for availability and pricing.
Open-End Timing Belt FAQs
Need Open-End Timing Belts?
Tell us the profile, pitch, width, length, and cord type. We will cut from roll stock and ship from Houston. Pre-welded loops also available.
