Conti Synchroflex T5 840

Conti Synchroflex T5 840 – classic PU timing belt with trapezoidal teeth

Conti Synchroflex T5 840 is an endless, cast polyurethane timing belt with 168 teeth, 5 mm tooth pitch and a pitch length of 840 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 cord line and is therefore the measurement that must be compared with the existing belt, the machine's spare parts 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: 840 mm
• Number of teeth: 168
• Tooth profile: T5
• Tooth pitch: 5 mm
• Material: cast polyurethane with steel cord
• Brand: Conti Synchroflex

The technical data below describes the part of the product that does not change when a different belt width is selected. Pitch length, tooth pitch and number of teeth remain identical for all width choices. However, the width affects the available belt cross-section width and the price calculated on the product page. Correct sizing must always take into account torque, speed, number of teeth in mesh, pulley diameters, service factor and any counter-bending.

Profile, tooth pitch and engagement

The T-profile is the classic metric timing belt profile with trapezoidal teeth and is described as a standard profile according to DIN 7721. It is used for general synchronous drives, positioning tasks and solutions with significant bending. The simple and proven geometry of the profile makes it widely used, but it still needs to be matched with a T-disc with the same tooth pitch. AT, HTD and other profiles are not automatically interchangeable.

Belt construction

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 specific product version

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.

Where is this profile used?

The profile series is used in practice for tasks such as office machines, household appliances, positioning drives and control drives. Common to these machines is the need for a fixed transmission ratio and controlled tooth meshing. A timing belt can transmit both force and position, but the capacity cannot be assessed based on length alone. Width, profile version, wrap angle and load cycle are among the data that must be included in the selection.

Disc geometry and tooth engagement

A belt of the correct length can still function poorly if the pulleys have the wrong profile, are worn or are misaligned. Therefore, check the tooth grooves, flanges, shaft alignment and the number of teeth on the pulleys. For T5, the nominal tooth pitch is 5 mm. The fixed tooth mesh makes the gear ratio reproducible, but only when the belt has sufficient wrap and does not run with constant side pressure.

How to avoid unnecessary wear and tear

Proper installation begins with clean, undamaged pulleys with the correct profile. Teeth and grooves should be checked for deposits, bars and wear before the new belt is fitted. The pretension should be based on the drive's calculation and should not be selected based on a random hand feel. After the initial run-in, it is a good idea to check grooveing, noise, temperature and whether the belt runs centrally.

From basic width to desired width

The basic price applies to 6 mm, and the other widths are calculated with the same percentage logic as the existing PU timing belts in the webshop. Integer widths from 6 to 50 mm can be selected on this product page. A width of twice the basic width therefore costs 100% more, while a width of one and a half times the basic width gives approximately 50% extra. This price rule is a webshop calculation; it does not replace a technical dimensioning of the belt's load-bearing capacity.

Checking teeth, back and edges

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 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.

Compare with the existing belt

It is not enough to compare the total circumference of a belt. The correct replacement must have the same pitch, tooth profile and number of teeth as the existing drive. The width must match the pulleys and the required capacity, and a DL or GEN III version must be identified separately. If in doubt, pictures of the marking, tooth profile and pulleys can be used as a supplement, but a documented spare part designation is best.

Questions and answers about this timing belt

Conti Synchroflex T5 840: 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 840 mm and the same number of teeth of 168. 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 T5 840: what is the difference between T5 and a GEN III belt?

This product is the standard version. GEN III is a separate reinforced series with red high-performance PU and denser, two-filament steel cord. The same profile and length therefore do not mean that the products are identical.

Conti Synchroflex T5 840: what does the steel cord mean for the function of the belt?

The steel cord tension members absorb the longitudinal tensile load and provide high longitudinal stiffness. This helps maintain pitch and position during operation. The cord must not be kinked, exposed or damaged during installation, as local damage can weaken the belt.

Conti Synchroflex T5 840: why is 6 mm chosen as the basic width?

6 mm is the width of the supplier item whose SKU is used as the main product's stock reference. Other widths are handled as choices under the same product because they are cut from the same type of timing belt sleeve. The base width also determines the percentage-based pricing in the webshop.

Conti Synchroflex T5 840: 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 T5 840: how to check if the length is correct?

Count the teeth and check the pitch. 168 teeth times 5 mm gives 840 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 T5 840: can a wider belt always transmit twice as much?

Not necessarily. A larger width provides a more active belt cross-section and can increase the permissible load, but the drive capacity also depends on the profile, number of teeth in mesh, pulley size, speed, load factor and preload. The width should be selected by an overall calculation.

Conti Synchroflex T5 840: can the width be measured with a regular caliper?

Yes, the belt width can usually be measured directly on the flat back or between clean, undamaged edges. However, the width is only one part of the identification. The profile, pitch length, number of teeth and any DL or GEN III version must also be correct.

The product in brief

Conti Synchroflex T5 840 is the correct size when the drive requires T5, 840 mm pitch length and 168 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.