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  Custom Timing Pulleys from SDP/SI


  • Custom Timing Pulleys


  • Designing a
    Drive System


  • Timing Belts



CUSTOM TIMING PULLEYS


When designing for power transmission applications, standard components provide a simple solution. Precision gears, timing belts, and pulleys are offered at SDP/SI in a wide variety of materials, types, and numbers of teeth for your consideration.

These inch and metric off-the-shelf components meet a wide range of requirements and can be purchased 24/7 at the SDP/SI E-Store where you can easily download product specifications and 3-D CAD models. Custom Timing Pulleys

When a custom solution is needed our engineers are ready to help. The SDP/SI engineering group specialize in drive systems and can assist with part selection, secondary operations, and custom designs ensuring the very best possible outcome for your need. Call (516) 328-3300.


center distance calculatorCenter Distance Designer
Get the right pulley and timing belt combination and instantly identify the appropriate part numbers that meet your specifications.


Custom Timing Pulleys - SDP/SI Capabilities:

  • Pulleys available in materials including:

    • Aluminum
    • Steel
    • Acetal with and without brass insert
    • Nylon
    • Polycarbonate with and without brass insert and metal hub



  • Plating Options:

    Zinc, Chrome and Nickel Plating, Anodizing Finishes, Passivation, Black Oxide Finishes



  • Available Pitches:

    • Miniature FHT® 1 mm
    • MXL .080”
    • 40 D.P.
    • XL 1/5”
    • L 3/8”
    • HTD® - 3 mm, 5 mm, 8 mm
    • GT®2 - 2 mm, 3 mm, 5 mm
    • GT®3 - 2 mm, 3 mm, 5 mm
    • T - 2.5 mm, 5 mm, 10 mm



  • Benefit from Our Expertise:

    Precision manufacturing superior mechanical components and custom pulley and belt drives since 1950.

    Over 170 machines – Get our Facility List here
    • CNC Swiss Turning
    • CNC Lathe (Mill-Turn)
    • CNC Milling & Machining Centers
    • Gear Cutting



  • 3D Printing:

    available onsite for your custom pulleys and drive assemblies, perfect for prototype and low-production runs.



  • Rapid Tooth Cutting Only Capabilities:

    proven performance, and reliability. Send Us Your Blanks for Precision Tooth Cutting – 3/16” to 4” OD



  • Cutting over 6,000 timing belts per day:

    SDP/SI is Gates’ largest timing belt processer in North America. Both stock and custom timing belt widths are expertly cut at our facility from a wide assortment of belt material inventory. Standard widths are available off-the-shelf for fast turnaround.





  • custom timing belt drive assembl

    Custom Synchronous Timing Belt and Pulley Drive Assemblies

    SDP/SI custom services deliver high-quality machined pulleys, molded parts, and synchronous timing belt and pulley drive systems to OEM customer requirements. As the engineer's preferred source, we produce an extensive selection of pulleys with custom features, including hub designs, fastening methods, and more for thousands of applications. Our unique Fairloc Hub design adds increased value, providing superior alignment and ease of adjustability not available elsewhere.

    Download our white paper and learn more about the Fairloc® design.


    Custom compound pulley and custom milled pulley

    When specifying a stock or custom pulley, it is important to consider the following:


    • Application

      As a pulley manufacturer our engineers have the experience to ensure you get the correct pulley for your specific application. From selecting a stock item to providing suggestions for modifications or a complete custom component, we can help make the most appropriate choice.


    • Power, torque, and workload requirements

    • Timing belt type

      Belt tooth profile, width, length, and pitch length.


    • Pulley dimensions and characteristics

      tooth profile, number of teeth, pitch diameter, width, hub style, bore, fastening method, material, and flange.


Timing Belts:


Timing belts are components of synchronous drives which represent an important category of drives.These drives employ positive engagement of two sets of meshing teeth. Hence, they do not slip and there is no relative motion between the two elements in mesh.

timing belts

Due to this feature, different parts of the drive will maintain a constant speed ratio or even a permanent relative position. This is extremely important in applications such as automatic machinery in which a definite motion sequence and/or indexing is involved.

The positive nature of these drives makes them capable of transmitting large torques and withstanding large accelerations.

Belt drives are particularly useful in applications where layout flexibility is important. They enable the designer to place components in more advantageous locations at larger distances without paying a price penalty. Motors, which are the largest heat source, can be placed away from the rest of the mechanism.

Start Designing Today!
We provide a library of technical information, design calculations, installation guidelines and much more to assist you in designing a drive system.

Synchronous Timing Belts:


Designing a Miniature Belt Drive System?
We not only have the components, but our engineers have put together a step-by-step guide with the appropriate engineering formulas to get you started. Download our white paper. Miniature Fenner timing belts and pulleys



Available Miniature Timing Belts:

  • FHT®1 (1 mm)
  • FHT®2 (2 mm)
  • FHT®3 (3 mm)
  • NOTE: FHT® is a registered trademark of Fenner Precision


One of the most common tooth profiles is a trapezoidal shape with sides being straight lines which generate an involute, like that of a spur gear tooth.The trapezoidal shape timing belt was superseded by a curvilinear tooth profile which exhibited some desirable and superior qualities.

Advantages of the curvilinear drive are as follows:
•  Proportionally deeper tooth: hence tooth jumping, or loss of relative position is less probable.
•  Lighter construction, with correspondingly smaller centrifugal loss.
•  Smaller unit pressure on the tooth since area of contact is larger.
•  Greater shear strength due to larger tooth cross section
•  Lower cost since a narrower belt will handle larger load.
•  Energy efficient, particularly if replacing a “V” belt drive which incurs energy losses due to slippage.
•  Installation tension is small, therefore, light bearing loads.

Belt construction for trapezoidal and curvilinear timing belts

Because of their superior load carrying capabilities, the curvilinear belts are marketed under the name Gates’ HTD (High Torque Drives) drives.Through continuous research a newer version of the curvilinear technology was developed by Gates, which was designated as Gates’ PowerGrip®GT2 followed by Gates’ PowerGrip®GT3.


Available Timing Belts:

  • 0.080” MXL
  • 40 D.P.
  • 1/5” XL
  • 3/8” L
  • 3 mm HTD
  • 5 mm HTD
  • 8 mm HTD
  • 2 mm GT2
  • 3 mm GT2
  • 5 mm GT2
  • 2 mm GT3
  • 3 mm GT3
  • 5 mm GT3
  • T2.5 (2.5 mm)
  • T5 (5 mm)
  • T10 (10 mm)

Pulleys for these timing belt profiles are usually available from manufacturers licensed by Gates Rubber Company. SDP/SI is one of the companies who can supply a full range of these pulleys. SDP/SI stock pulleys and custom pulleys are machined and molded to precisely mesh with the different tooth profiles ensuring a superior drive system.