Connecting and Joining Timing Belts
Connecting and Joining Timing Belts
Open-ended polyurethane timing belts can be joined into endless loops using several connection methods, each offering different strength, installation speed, and equipment requirements. The right method depends on your belt pitch, load requirements, installation environment, and whether the joint needs to be permanent or reopenable.
Texas Belting provides connection kits, splicing services, and field welding support for all polyurethane timing belt profiles. For ATN Convertible belts, dedicated ATN connecting kits are available in three strength grades. For belts that will never need to be reopened, truly endless (no joint) configurations from the polyurethane timing belts catalog provide the smoothest operation and longest life.
- Finger splice: 80% to 85% of belt strength
- Butt weld: 60% to 70% of belt strength
- Mechanical connector: 40% to 50% of belt strength
- Hook joint: 30% to 40% of belt strength
- ATN kits: C, DC, and DC-PRO grades
- PinLock kits for multiple pitches
- Field welding for factory-equivalent joints
- Truly endless (no joint) also available
Available Connection Methods
| Method | Compatible Pitches | Strength | Best For |
|---|---|---|---|
| Timing Belt Lock | AT10, T10 | Moderate | Quick field installation, moderate loads |
| PinLock connecting kit | Multiple pitches | Moderate to high | Versatile field connection with rated force capacity |
| ATN connecting kit (C) | ATN10, ATN12.7, ATN20 | Moderate | Standard ATN belt installation |
| ATN connecting kit (DC) | ATN10, ATN12.7, ATN20 | High | Higher load ATN applications |
| ATN connecting kit (DC-PRO) | ATN10, ATN12.7, ATN20 | Maximum | Professional ATN installation, maximum reliability |
| Field welding | All pitches | Factory-equivalent | Permanent, highest-strength field joint |
| Tooth bar inserts | Various | Moderate | Mechanical clamping for linear drive ends |
Joint Strength Comparison
The table below compares joint types by percentage of original belt rated capacity. Higher percentages mean the joint retains more of the belt's original tensile strength.
| Method | Joint Strength (% of belt) | Field Installable | Equipment Needed | Best For |
|---|---|---|---|---|
| Finger splice (welded) | 80% to 85% | No (factory or trained technician) | Heat press, tooling | Maximum strength, smooth operation |
| Butt weld | 60% to 70% | No (factory) | Heat press | Short belts, low to moderate loads |
| Mechanical connector | 40% to 50% | Yes | Hand tools only | Field replacement, quick installation |
| Hook joint | 30% to 40% | Yes | Hand tools only | Light-duty, frequent belt changes |
Selecting the Right Connection
| Your Priority | Recommended Method |
|---|---|
| Maximum joint strength | Finger splice with thermal welding (80% to 85%) |
| Smooth, vibration-free operation | Finger splice (longest joint area, most gradual transition) |
| Quick field installation (no special equipment) | Mechanical connector or hook joint |
| Frequent belt changes | Hook joint (tool-free disconnect and reconnect) |
| Food-grade / hygienic requirements | Finger splice (no metal hardware in the joint) |
| ATN convertible belt installation | ATN DC-PRO kit (highest ATN joint strength) |
Field Welding
A portable field welding unit produces permanent, thermally welded joints on-site that match factory weld strength. This is the preferred method when belt length must be determined during installation and maximum joint strength is required. Field welding is available for all pitches and belt widths. Contact Texas Belting at 888-203-2358 for field welding service availability.
Frequently Asked Questions
Connection methods include finger splicing (interlocking fingers welded together, 80% to 85% strength), butt welding (straight joint, 60% to 70%), mechanical connectors (metal joining plates, 40% to 50%), and hook joints (30% to 40%). For ATN belts, dedicated connecting kits are available in three strength grades (C, DC, DC-PRO).
Finger splicing provides the highest joint strength, typically reaching 80% to 85% of the belt's original rated capacity. The interlocking finger design distributes stress across a wider area than butt welds or mechanical joints. For 100% strength, specify a truly endless belt (no joint at all).
Yes. Mechanical connectors and hook joints can be installed in the field with hand tools only, no special equipment needed. Field welding with portable equipment is also available for factory-equivalent joint strength on site. Finger splicing requires heat press equipment and is typically performed at the factory or by trained technicians. Contact Texas Belting at 888-203-2358 for field connection support.
No. A welded finger splice creates a permanent joint that cannot be non-destructively separated. If the belt needs to be removed for maintenance, the splice must be cut and a new splice made. For applications requiring frequent belt removal, mechanical connectors or hook joints are more practical.
Finger splicing is generally available for belt widths of 16mm and wider. Narrower belts (10mm and below) may be limited to butt welding or mechanical connection due to the small cross-section available for finger interleaving.
A finger splice typically requires 30 to 60 minutes of skilled labor including cutting the finger pattern, aligning the belt ends, and heat-pressing the weld. Factory splicing is recommended for consistent quality. Field splicing with portable heat press equipment is available through Texas Belting for on-site installations.
Finger splicing has the highest labor cost but provides the best performance and longest joint life. Mechanical connectors have moderate material cost with minimal labor. Hook joints are the lowest cost option. The right choice depends on whether you prioritize joint strength, installation speed, or total cost of ownership over the belt's service life.
No. Only identical belts (same pitch, width, material, and tension member) can be spliced together. Joining different belt types would create a mismatch in tooth engagement, tension member alignment, and belt thickness that would cause immediate drive problems.
Need Belt Connection Kits or Splicing?
Send us your belt profile, width, and length. We will recommend the right connection method and provide kit pricing or splicing service quotes.