Resources
Belts, Pulleys, and SheavesMPTA Bulletins on Belts, Pulleys, and Sheaves
MPTA B3c – Synchronous Drive Identification Informational Bulletin (MPTA B3c-2020 R2025)
MPTA-B3c-2020 R2025 provides standard groove dimensions for current and discontinued synchronous drive products. The standard promotes compatibility among timing belts and pulleys from multiple manufacturers by defining key geometric parameters such as tooth spacing, depth, and form. It supports precision alignment, efficient power transmission, and long component life in synchronous belt drive systems.
MPTA B11i – Belt Drive Misalignment Informational Bulletin (MPTA-B11i-2018 R2024)
Proper alignment is crucial for optimal belt service life and performance. This informational bulletin provides information on belt drive misalignment and recommendations for maximum misalignment angles for V-belt, V-ribbed, and synchronous belt drives. It also provides a formula for calculating the allowable misalignment offset based on the center distance, and includes a table with the maximum allowable misalignment offsets for different center distances.
MPTA Standards on Belts, Pulleys, and Sheaves
MPTA B1c – Bore and Keyway Tolerances for V-Belted Sheaves (MPTA-B1c-2010 R2025)
MPTA-B1c-2010 R2025 establishes standard dimensions for keyways and setscrews used in power transmission hubs and bores. By defining consistent keyway widths, depths, and setscrew placements, this standard promotes interchangeability and reliable performance across manufacturers. It applies to a range of bushing, pulley, and hub types commonly used in mechanical power transmission systems, ensuring compatibility between components from different producers.
MPTA B2c -Standard Practice Sheave / Pulley Balancing (MPTA-B2c-2017 R2024)
The MPTA-B2c-2017 (R2024) Standard Practice for Sheave/Pulley Balancing establishes balance tolerances and methods for power transmission sheaves and pulleys. It covers both one-plane (static) and two-plane (dynamic) balancing, ensuring smooth operation, reduced vibration, longer bearing life, and optimal performance.
The standard applies to sheaves and pulleys used with V-belts and synchronous belt drives and includes detailed formulas for determining acceptable unbalance based on product size, material, and operating speed.
MPTA B4c – Standard Surface Finish for Transmission Pulleys (MPTA-B4c 2024)
The MPTA-B4c-2024 Standard Surface Finish for Transmission Sheaves & Pulleys defines the maximum allowable surface roughness for key areas of transmission sheaves and pulleys before coating. The standard covers v-groove sheaves, cylindrical (flat) pulleys, and synchronous pulleys, providing uniform reference values for manufacturing and inspection. Surface roughness measurements are aligned with ASME-B46.1. This document helps ensure consistent performance, interchangeability, and product quality across manufacturers.
MPTA B6c – Quick Detachable Bushing and Mating Hub (MPTA-B6c-2020)
The MPTA-B6c-2020 Quick Detachable Bushing & Mating Hub Standard establishes dimensional guidelines and tolerances for inch and metric QD bushings and hubs. This ensures interchangeability among products from different manufacturers. Covering bushing and hub geometries, fastener requirements, and mounting arrangements, the standard applies to systems featuring external flanges, split designs, and ¾-inch-per-foot tapers on diameter. It includes detailed data tables for both inch and metric configurations, promoting consistent performance and compatibility throughout the industry.
MPTA B7i – Calculation of V-Belt Tensions And Shaft Loads (MPTA-B7i-2024)
V-Belts will transmit power satisfactorily over a wide range of tensions. An experienced user can develop a “feel” when a drive is tensioned within this range. However, to optimize belt life and performance and to avoid undue stress on shafts and bearings it is desirable to calculate and measure belt tension based on drive loads. This standard provides a method for calculating and measuring V-Belt tensions and for calculating shaft loads associated with these tensions on two-sheave locked center drives.
MPTA B8i – Sheave Arm Stress Formula (MPTA-B8i-2011 R2016)
MPTA-B8i-2011-R2016 presents formulas for calculating bending stresses in the arms of V-belt sheaves. The standard identifies variables affecting stress—such as torque, belt tension, sheave geometry, and arm design—and establishes consistent methods for evaluating strength and safety margins. These calculations help manufacturers and engineers ensure that sheave designs meet performance and durability requirements while maintaining compatibility across the industry.
MPTA B9i – Taper-Lock Bushing & Mating Hub Standard (MPTA-B9i-2020)
MPTA-B9i-2020 defines the general dimensions and tolerances for Taper-Locking bushings and their mating hubs. Designed to promote interchangeability between manufacturers, it standardizes systems featuring an 8-degree included taper and full-length split bushings. The document includes complete dimensional data for bushings and hubs from size 1008 through 120100, helping ensure consistent fit, performance, and manufacturing alignment across the mechanical power transmission industry.
MPTA B10i – Split Taper Bushing Standard (MPTA-B10i-2020)
MPTA-B10i-2020 establishes dimensional data and tolerances for Split Taper bushings and mating hubs used in mechanical power transmission. It provides detailed reference tables to ensure that bushings and hubs from different manufacturers are fully interchangeable. Covering key features such as taper, keyway, flange, and fastener dimensions, this standard supports consistency, safety, and compatibility across a wide range of drive systems.
MPTA B13i – Rim Speed Limits Standard (MPTA-B13i-2013 R2025)
The MPTA-B13i-2013 R2025 – Rim Speed Limits standard provides guidance on the maximum allowable rim speeds for industrial V-belt sheaves and synchronous belt pulleys. Based on material type and construction, the standard defines recommended operating limits to ensure safe, reliable performance, and includes a conversion formula for calculating rotational speed (RPM) from rim speed (FPM).
ARPM Belt Drive Publications
The following publications are prepared in collaboration with the member companies of the Association for Rubber Products Manufacturers (ARPM). These publications are available for purchase from this page on the ARPM website.
- IP-20 Classical Multiple V-Belts (A,B,C., D, and E Cross Sections)
- IP-21 Double V-Belts (AA, BB, CC, and DD Cross Sections)
- IP-22 Narrow Multiple V-Belts (3V, 5V, and 8V Cross Sections)
- IP-23 Single V-Belts (2L, 3L, 4L, and 5L Cross Sections)
- IP-24 Synchronous Belts (MXL, XL, L, H, XH, and XXH Belt Sections)
- IP-25 Variable Speed V-Belts (12 Cross Sections)
- IP-26 V-Ribbed Belts (H, J, K, L, and M Cross Sections)
- IP-27 Curvilinear Toothed Synchronous Belts (H3M, R3M, S3M, H5M, S5M, H8M, R8M, S8M, H14M, R14M, S14M, H20M, and R20M Belt Pitches)