AT20 Timing Belts (20mm Modified Metric Trapezoidal)

Q: Are AT20 belts available in open-end form?

Yes. Open-end AT20 with steel cord available for extreme-load linear motion. Sold by the meter. Lead times may be longer than smaller AT profiles.

Q: What pulleys work with AT20 timing belts?

AT20 requires AT20 profile pulleys. Large due to 20mm pitch. Not compatible with any other profile. Typically sourced from specialized European suppliers.

Q: How does AT20 compare to XXH?

AT20 (20mm, polyurethane, European AT standard) and XXH (31.75mm, neoprene, ANSI standard) are both extreme-load profiles from different systems. Different pulleys, not interchangeable. AT20 offers urethane advantages; XXH has the largest ANSI tooth depth.

Q: Is AT20 a stock item or special order?

AT20 is a specialty pitch. Some sizes may be in stock, but many are made to order with 2 to 4 week lead times. Call 888-203-2358 early to confirm.

Q: How do I measure an AT20 timing belt for replacement?

Measure total outside length, count teeth, measure width. Pitch should be 20mm center to center. Verify AT profile (wider base, straight sides).

Q: Is AT20 available in food-grade material?

FDA-compliant polyurethane is technically available but food-grade AT20 is very uncommon. Most food applications use smaller AT profiles (AT5, AT10). Contact Texas Belting to confirm.

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AT20 Timing Belts (20mm Modified Metric Trapezoidal)

AT20 timing belts are the largest and heaviest pitch in the AT-profile family. With a 20mm pitch and the AT-profile's optimized wider tooth base, AT20 belts deliver the maximum load capacity available in the modified metric trapezoidal system. These belts are engineered for the most extreme applications in European-designed automation: the largest gantry systems, heavy bridge crane positioning, massive CNC and cutting table gantries, and industrial material handling drives where no other belt profile provides enough capacity.

AT20 timing belts are manufactured from polyurethane with steel wire or Kevlar tensile cords and are available in both closed-loop and open-end (continuous roll) form. Open-end AT20 with steel cord is specified for the absolute heaviest linear motion and positioning applications. Texas Belting sources AT20 timing belts from leading European manufacturers.

AT20 quick specs:
Pitch: 20mm (0.787")
Tooth profile: Modified trapezoidal (AT, wider tooth base)
Profile family: AT-Profile (AT3, AT5, AT8, AT10, AT15, AT20)
Standard widths: 50, 75, 100, 150mm
Primary material: Polyurethane with steel cord (standard); Kevlar cord available
Temperature range: -22°F to +176°F (-30°C to +80°C) standard
Formats: Closed-loop (welded endless) and open-end (continuous roll)

Need AT20 timing belts?

AT20 is a specialty profile. Send us your part number, equipment model, or application details. We will confirm availability, lead time, and pricing.

Request a Quote 888-203-2358

AT20 Part Number Decoder

Standard Format: [Pitch Length]AT20-[Width]

Part Number	Pitch Length	Width	Teeth	Construction
1000AT20-50	1000mm	50mm	50	Urethane, steel cord
1600AT20-75	1600mm	75mm	80	Urethane, steel cord
2200AT20-100	2200mm	100mm	110	Urethane, steel cord
3000AT20-150	3000mm	150mm	150	Urethane, steel cord
AT20-100 (open-end)	Per cut length	100mm	Per length	Urethane, steel cord

How to calculate teeth: Divide pitch length by 20. Example: 2200 / 20 = 110 teeth. Open-end AT20 belts are sold by the meter and cut to any required length. Some manufacturers reverse the format (for example, 100AT20-2200). Texas Belting can cross-reference AT20 part numbers from any manufacturer. Call 888-203-2358 or send us your part number.

AT20 Width Guide

Width (mm)	Width (Inches approx.)	Typical Applications
50mm	1.97"	Lightest AT20 drives. Consider AT15 for lighter loads at this width.
75mm	2.95"	Medium-heavy AT20 applications, large gantry systems
100mm	3.94"	Most common AT20 width. Extreme-load gantries, heavy CNC.
150mm	5.91"	Maximum standard AT20 width. The absolute heaviest belt-driven applications.

AT20 belts at widths above 150mm may be available on a custom basis from select manufacturers. Contact Texas Belting for availability.

AT20 vs. Other Extreme-Load Timing Belt Options

Profile	Pitch	Tooth Form	Load Capacity	Best For
AT10	10mm	Modified trapezoidal (AT)	Very heavy	Standard heavy AT-profile. Most popular heavy-duty AT pitch.
AT15	15mm	Modified trapezoidal (AT)	Extreme	Very heavy gantries, large CNC, step below AT20
AT20	20mm	Modified trapezoidal (AT)	Maximum	Largest AT-profile. Absolute heaviest belt-driven positioning.
14M (HTD)	14mm	Curvilinear (HTD)	Very heavy	Heaviest standard HTD pitch, global standard
XXH	31.75mm (1-1/4")	Trapezoidal (ANSI)	Extreme	Largest ANSI trapezoidal. Neoprene. Mining, steel, heavy industry.
Poly Chain GT Carbon	8mm / 14mm	Modified curvilinear (GT)	Extreme	Chain drive replacement. Narrow width at extreme torque.

AT20 is the largest pitch in the AT-profile system and represents the upper limit of belt-driven positioning in the European AT standard. For applications that exceed even AT20 capacity, the drive typically transitions to chain, gear, or rack-and-pinion systems. XXH (1-1/4" pitch) is the closest ANSI equivalent in terms of extreme load capacity, but uses neoprene construction and a different tooth form. See the Timing Belt Tooth Profiles Explained guide for full comparisons.

AT20 for Extreme Linear Motion

AT20 is specified only for the most extreme linear motion applications, where AT15 has reached its limits. These are typically the largest gantry systems in industrial automation: multi-ton bridge gantries, very heavy stone slab processing tables, large ship-building positioning systems, and custom heavy material handling equipment.

Open-end urethane AT20 with steel cord is the standard construction. Cut to any length. Joined with heavy-duty mechanical connectors or welded splices.
100mm width is the most common for AT20 applications. 150mm for the absolute heaviest loads.
Steel cord provides 0.02% elongation under load, critical for maintaining positioning accuracy on gantry travel distances of 10 meters or more.
AT20 pulleys are large due to the 20mm pitch. Minimum pulley diameter is significantly greater than AT15. Verify space constraints before specifying AT20.

For more detail on urethane belt options for linear motion, see Urethane Timing Belts and Timing Belts for Linear Motion.

AT20 Timing Belt Materials

Property	Steel Cord (Standard)	Kevlar Cord
Elongation	0.02% (near-zero)	0.3 to 0.5%
Best for	Extreme linear motion, heavy positioning	Rotary drives where flex life is critical (rare at this pitch)
Minimum pulley size	Large (steel is stiff, 20mm pitch requires large pulleys)	Slightly smaller minimum (Kevlar flexes tighter)
Chemical resistance	Excellent (urethane body)	Excellent (urethane body)
FDA available	Yes (limited availability at this pitch)	Yes (limited)
Open-end available	Yes (standard)	Yes (less common)

AT20 belts are manufactured exclusively from polyurethane. Neoprene AT20 belts are not produced. Steel cord is the standard and most common cord type for AT20 due to the heavy-load nature of AT20 applications.

Common AT20 Timing Belt Applications

Application	Why AT20	Typical Width
Extreme-load gantry systems	Maximum AT-profile capacity for multi-ton carriage positioning	100 to 150mm
Large-format stone processing tables	Very heavy slab positioning with long travel and high precision	100 to 150mm
Heavy bridge crane positioning	Belt-driven bridge travel on the largest crane gantries	100 to 150mm
Shipbuilding and marine positioning	Extreme-load positioning for large structural components	100 to 150mm
Large CNC and cutting tables	Very heavy gantry with long travel on the largest machines	75 to 100mm
Custom heavy material handling	Belt-driven positioning for the heaviest automated material transport	75 to 150mm
Heavy industrial automation (European)	Original equipment specified AT20 on the largest European systems	75 to 100mm
Specialty heavy positioning	Telescope, antenna, and large equipment positioning drives	50 to 100mm

AT20 is a specialty pitch used in a small number of extreme-load applications. For most heavy-duty timing belt needs, AT10 or AT15 will provide sufficient capacity. See the Timing Belt Selection Guide for help determining the right profile and pitch.

AT20 Timing Belt Brands We Carry

Brand	AT20 Product Lines	Notes
Gates	Limited AT20 availability	AT20 is outside Gates' standard range. Special order.
Continental / ContiTech	Synchroflex AT20	Leading manufacturer of large-pitch AT-profile urethane
Bando	Bando AT20	Available on special order
Diesel Belting	Diesel AT20	Limited availability at this pitch
Megadyne	Megalinear AT20	Open-end specialist. Strong large-pitch AT range.

AT20 is a specialty pitch with longer lead times than smaller AT profiles. Continental and Megadyne carry the broadest AT20 range. Call 888-203-2358 with your requirements for current availability and lead time.

AT20 Timing Belt FAQs

What does AT20 mean on a timing belt?

AT20 refers to a modified metric trapezoidal timing belt with a 20mm pitch. The "AT" stands for Advanced Trapezoidal. AT20 is the largest pitch in the AT-profile family (AT3, AT5, AT8, AT10, AT15, AT20) and delivers the maximum load capacity available in the modified metric trapezoidal system.

When should I choose AT20 over AT15?

Choose AT20 only when AT15 at maximum width does not provide enough load capacity for your application. AT20 is a specialty pitch for the most extreme belt-driven positioning systems. AT20 requires very large pulleys due to the 20mm pitch, so verify space constraints before specifying. For most heavy-duty applications, AT10 or AT15 will provide sufficient capacity.

Are AT20 belts available in open-end form?

Yes. AT20 timing belts are available in open-end (continuous roll) polyurethane with steel cord. Open-end AT20 is the standard format for extreme-load linear motion. Sold by the meter and cut to any required length. Lead times may be longer than smaller AT profiles due to the specialty nature of this pitch.

What pulleys work with AT20 timing belts?

AT20 timing belts require pulleys machined with the AT20 tooth profile. AT20 pulleys are large due to the 20mm pitch and are not compatible with any other profile, including AT15, AT10, or XXH. AT20 pulleys are typically available from specialized European suppliers. Contact Texas Belting for sourcing assistance. See the Timing Belt Sprocket Selection Guide.

How does AT20 compare to XXH?

AT20 (20mm modified trapezoidal, polyurethane) and XXH (31.75mm/1-1/4" trapezoidal, neoprene) are both extreme-load timing belt profiles but come from completely different systems. AT20 uses polyurethane with steel cord and follows the European AT standard. XXH uses neoprene with fiberglass cord and follows the ANSI/RMA standard. They require different pulleys and are not interchangeable. AT20 offers urethane advantages (chemical resistance, low particulate, open-end) while XXH provides the largest tooth depth in the ANSI system.

Is AT20 a stock item or special order?

AT20 is a specialty pitch. Some common sizes and open-end roll widths may be in stock, but many AT20 sizes are made to order with lead times of 2 to 4 weeks depending on the manufacturer and specifications. Call 888-203-2358 early in your project timeline to confirm availability and lead time for your specific AT20 requirements.

How do I measure an AT20 timing belt for replacement?

Measure the total outside length, count the number of teeth, and measure the belt width. The tooth pitch should measure 20mm from center to center. Verify the tooth profile is AT (wider base with straight sides). Check for the part number printed on the belt back. For detailed instructions, see How to Measure a Timing Belt.

Is AT20 available in food-grade material?

FDA-compliant polyurethane is technically available for AT20 belts, but food-grade applications at this pitch size are very uncommon. Most food processing equipment uses smaller AT profiles (AT5, AT10) where FDA-compliant grades are readily stocked. Contact Texas Belting to confirm food-grade AT20 availability for your specific application.

Need AT20 Timing Belts?

AT20 is a specialty profile. Send us your part number, belt dimensions, or application details. We will confirm availability, lead time, and pricing.

Request a Quote

888-203-2358