Conti Synchroflex T10 690

Conti Synchroflex T10 690 – precise T-profile timing belt in cast polyurethane

When a timing belt needs to be replaced correctly, the profile, pitch length and number of teeth are the first data that must be correct. The Conti Synchroflex T10 690 has a T10 profile, 10 mm tooth pitch, 690 mm pitch length and 69 teeth. This makes the product unique on the length and profile side, while the belt width is selected separately on the product side. The belt is manufactured as an endless Conti Synchroflex PU timing belt with steel cord. 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: 690 mm
• Number of teeth: 69
• Tooth profile: T10
• Tooth pitch: 10 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.

Profile, tooth pitch and engagement

The trapezoidal T-geometry is a standardized solution for synchronous transmission. The teeth mesh with corresponding grooves in the timing belt pulley, so that the speed ratio is maintained without slipping. The correct pitch is crucial: a T5 belt, for example, will not fit in an AT5 pulley simply because the tooth pitch is 5 mm in both places. The shape and clearance of the tooth flanks are different.

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 product is the regular Conti Synchroflex standard version in the specified profile. Standard and GEN III may have the same pitch length and number of teeth, but they are different product series with different material construction and capacity data. The same applies to a DL belt, which has teeth on both sides. When reordering, the entire profile designation should therefore be checked, not just the length.

Where is this profile used?

The application examples in the catalogue include machine tools, main and auxiliary drives, textile machines and printing machines. This shows that the profile can be used in both power transmission and motion control. However, the specific belt must only be finally selected when the machine's torque, speed, center distance and pulley geometry are known. When simply replacing a spare part, the safest method is usually to copy the documented profile, length, design and width.

Timing belt pulleys and transmission ratios

The tooth profile of the timing belt pulleys must correspond to the T10 of the belt, and their pitch must be 10 mm. The transmission ratio is determined by the ratio of the number of teeth of the pulleys, not by the width of the belt. A larger pulley usually reduces the bending load, while a very small pulley gives more bending per revolution. The angle of engagement and the number of teeth in mesh must be sufficient for the current load.

Practical advice for installation

When installing, the cord pullers must be protected against kinks and local pressure damage. The belt must not be pinched with pliers or a screwdriver, and it should not be folded sharply. Check that the pulleys have the same pitch and profile as the belt and that they are not worn out. A stable drive is achieved through the right combination of alignment, wrapping and calculated pretension.

Choosing belt width

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.

Prevention of early belt damage

Uniform light polishing of the tooth flanks may be normal, but localised spalling, ctiming baring or severe wear should be investigated. Wear on one edge often indicates misalignment or persistent flange contact. Damage to tooth tips may be due to incorrect profile, foreign bodies or inadequate engagement. If cord becomes visible or the belt has a sharp break, it should not continue in service without assessment.

Operating environment and maintenance

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 sizing. The service life is not only affected by the material, but also by load peaks, bending, pulley size, alignment and environment. Keep the drive clean and do not remove deposits with sharp tools that could damage the teeth. If the belt operates in chemically exposed areas, food environments, clean rooms or at extreme temperatures, a suitable special design should be considered.

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.

Frequently Asked Questions

How many teeth does the Conti Synchroflex T10 690 have?

The belt has 69 teeth. The number of teeth is calculated by dividing the pitch length of 690 mm by the tooth pitch of 10 mm. The result is 69, 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 T10 690: how to check if the length is correct?

Count the teeth and check the pitch. 69 teeth times 10 mm gives 690 mm pitch length. Then compare the profile and design with the marking or the machine's spare parts list. A measurement around the outside of the belt alone is not accurate enough.

Conti Synchroflex T10 690: what is the difference between tooth pitch and pitch length?

The tooth pitch is the distance from one tooth to the next and is 10 mm for this profile. The pitch length is the entire nominal circumference in the cord line and is 690 mm. When the pitch length is divided by the tooth pitch, the belt has 69 teeth.

Conti Synchroflex T10 690: can the belt be used for precise positioning?

The tooth engagement provides a positive, synchronous transmission without the normal slippage of a friction belt. This makes the profile relevant for positioning tasks, but the achievable accuracy also depends on the quality of the pulleys, shaft play, belt pretension, load and the overall machine design.

Conti Synchroflex T10 690: how does preload affect operation?

Correct pretension keeps the teeth in stable engagement and reduces the risk of tooth jump. Too low a tension can cause impact and jump under load, while too high a tension increases the load on the cord, pulleys and bearings. The correct value must be determined based on the drive's dimensioning.

Conti Synchroflex T10 690: 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 T10 690: can this belt be used at high rpm?

The Conti Synchroflex series is designed for precise and fast synchronous drives, but the permissible speed depends on the profile, pulley diameter, belt width, load and peripheral speed. A high speed must therefore not be approved based on the product name alone; the drive must be calculated.

Conti Synchroflex T10 690: 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, 69 teeth at 10 mm pitch gives a length of 690 mm. It is a simple check that often reveals faults that are not visible by a quick comparison of two loose belts.

The most important thing about this size

Conti Synchroflex T10 690 is the correct size when the drive requires T10, 690 mm pitch length and 69 teeth. The belt is cast endless in PU with steel cord and must be used with timing belt pulleys that match the profile. Choose the width according to the technical load and always check the design, alignment and pretension before commissioning.