PU timing belt AT3 816 - Conti® Synchroflex

Conti Synchroflex AT3 816 – durable PU timing belt with stable tooth pitch

Conti Synchroflex AT3 816 is an endless, cast polyurethane timing belt with 272 teeth, 3 mm tooth pitch and a pitch length of 816 mm. It is intended for synchronous power transmission, where the driving and driven shafts must follow a fixed tooth ratio without the slippage known from friction-based belt drives. The pitch length is the nominal length measurement in the belt's cord line and is therefore the measurement that must be compared with the existing belt, the machine's spare part data and the installed timing belt pulleys. This is the standard version in the specified profile. It must not be confused with a possible GEN III version or a double-sided DL belt with the same pitch length.

Key technical data

• Pitch length: 816 mm
• Number of teeth: 272
• Tooth profile: AT3
• Tooth pitch: 3 mm
• Material: cast polyurethane with steel cord
• Brand: Conti Synchroflex

The list gathers the information normally used to identify a timing belt: nominal length, number of teeth, profile, material and make. It is important to read all the information together. Two belts can have the same pitch length but be incompatible if the tooth profile or tooth pitch is different. Conversely, a different width does not change the number of teeth as long as the profile and pitch length are the same.

Why the correct profile is crucial

The metric AT geometry has trapezoidal teeth with a larger tooth volume than the standard T profile. The purpose is to distribute the load advantageously in the tooth mesh and achieve higher tooth strength without making the drive unnecessarily large. The profile requires suitable AT timing belt pulleys with the same pitch; a visual similarity to other profiles is not evidence of compatibility.

How the Conti Synchroflex belt is constructed

With the cast manufacturing method, the finished belt becomes an exact copy of a precision-machined shape. This is a major reason for the uniform tooth pitch and reproducible length. The steel cord is integrated into the polyurethane and contributes to position and angular precision. The design is suitable for synchronous drives, where a conventional elastic friction belt does not provide the desired repeatability.

The execution must be correctly identified

The standard version is selected when the supplier's article data does not specify GEN III or DL. This is an important product distinction, because different versions can share both profile and length. Therefore, on this product page, it is the standard version that is described. The belt width can be selected, but the basic construction and tooth geometry are not changed.

Areas of application

Continental cites small power drives, handling equipment, compact positioning axes and light synchronous drives as examples for this profile family. The examples describe the general application area of ​​the profile, but are not an approval for any specific installation. The final belt width and pretension must be selected based on the transmitted torque, starting and shock loads, operating time, pulley sizes, speed and the number of teeth in simultaneous engagement. For safety-critical or heavily loaded drives, an actual calculation should be made.

How the width variants work

The belt width is not written in the product name because the same pitch length is collected on one product page. The starting pu is 6 mm. Integer widths from 6 to 50 mm can be selected on this product page. The original supplier widths for this length are 6, 8, 10, 12, 16, 20, 25, 32 and 50 mm. Other intermediate sizes are offered as cut-to-size versions of the same type of timing belt sleeve when they are within the selection shown. The number of teeth, pitch length and profile do not change when the width is changed.

Gear ratio, enclosure and tooth contact

The number of teeth on the pulleys affects both the gear ratio, deflection and how many belt teeth carry the load. A small pulley may be necessary in a compact drive, but it should not be selected without considering the minimum profile requirements and any counter deflection. Use timing belt pulleys with 3 mm pitch and the correct AT3 tooth shape, and check that the flanges do not damage the belt edge.

How to avoid unnecessary wear and tear

The belt must be able to be placed on the pulleys without force. If it can only be mounted by forcing it over a flange, the center distance or mounting procedure is incorrect. The pulley shafts must be aligned and the flanges must be smooth and undamaged. In the case of multi-shaft or counter-bent drives, the diameter and position of the rollers must be assessed separately. Correct pretensioning reduces the risk of tooth skipping without unnecessarily loading the bearings.

Before ordering a replacement

When replacing a spare part, the marking on the existing belt should be compared with the product name. Check the profile designation, pitch length, number of teeth, design and width. If the text on the belt has worn away, the number of teeth can be counted and the pitch can be assessed by measuring over several teeth. A single external length measurement is less reliable because the nominal length of the timing belt is indicated in the pitch line.

Checking teeth, back and edges

Troubleshooting should start with pu location of the damage. Edge wear is typically associated with grooveing and alignment, while tooth skipping can be associated with too low tension, load peaks or too few teeth in mesh. Ctiming bars on the back can be caused by too small rollers, back bending or environmental influences. Do not simply replace the belt without also finding the mechanical cause.

Temperature, media and service

The standard material is specified for ambient temperatures from -30 °C to +80 °C. Applications close to the limits, especially below -10 °C or above +50 °C, may require special dimensioning. The timing belt operates without lubrication, and oil or grease should therefore not be added to dampen noise. The polyurethane is described as resistant to aging as well as simple oils, grease and petrol and to certain acids and bases. In the case of permanent contact, cleaning chemicals or unknown media, material compatibility should be specifically clarified.

Technical questions about the product

Conti Synchroflex AT3 816: why is the number of teeth important for spare parts?

The number of teeth links the pitch of the profile to the nominal length of the belt. For this size, 272 teeth at 3 mm pitch gives a length of 816 mm. It is a simple check that often reveals faults that are not visible by a quick comparison of two loose belts.

Conti Synchroflex AT3 816: does the number of teeth change when the belt width is changed?

No. All width choices on this product page have the same pitch length of 816 mm and the same number of teeth of 272. Only the width of the belt, and thus the price and possible load capacity, changes. The width must still match the pulleys and the technical dimensioning.

Conti Synchroflex AT3 816: are the standard widths the only possible widths?

The documented supplier widths for this size include 6, 8, 10, 12, 16, 20, 25, 32 and 50 mm. The product page may also show intermediate sizes as cut widths when they are within the allowed range. This does not change the tooth profile or length, but the price is calculated based on the base width.

Conti Synchroflex AT3 816: does this PU timing belt need to be lubricated?

No. The timing belt is designed for lubrication-free operation. Oil or grease should not be added to reduce noise as this may mask an alignment, pretension or worn pulley problem. Instead, keep the tooth mesh clean and check the cause of any abnormal noise.

Conti Synchroflex AT3 816: why can a timing belt make noise?

Noise can be caused by incorrect pretension, skewed pulleys, poor tooth profile compatibility, excessive speed, resonance or worn tooth grooves. Lubrication is not the solution. First check alignment, tension, pulley condition and whether the belt runs without abnormal side contact.

How many teeth does the Conti Synchroflex AT3 816 have?

The belt has 272 teeth. The number of teeth is calculated by dividing the pitch length of 816 mm by the tooth pitch of 3 mm. The result is 272, and this number can be used as an additional check when identifying an existing belt. A different number of teeth means a different pitch length.

Conti Synchroflex AT3 816: how to check if the length is correct?

Count the teeth and check the pitch. 272 ​​teeth times 3 mm gives 816 mm pitch length. Then compare the profile and design with the marking or the machine parts list. A measurement around the outside of the belt alone is not accurate enough.

The product in brief

The product brings together the specified AT3 profile and length on one side, so that the appropriate width can be selected without creating a separate item for each cut. The main technical data is 816 mm pitch length and 272 teeth. If in doubt about load or pulley compatibility, the drive should be calculated before ordering the belt.