The Z-Series 3/8" Sq. Dr. Socket Set with 72 Tooth Ratchet is a versatile and comprehensive 26-piece toolset designed for a wide range of applications. This set includes 3760Z extension bars in lengths of 75, 125, and 250 mm for extended reach, along with 3400MZ standard length 6-point sockets in sizes 5.5, 6, 7, 8, 10, 12, 13, 14, 17, 19, 21, and 22 mm. Additionally, it features 3300MZ deep 6-point sockets in sizes 8, 10, 12, and 14 mm, as well as 3300CZ spark plug sockets in sizes 14, 16, and 20.8 mm. For enhanced versatility, the set includes a quick spinner for fast manual adjustments, a 72-tooth ratchet for smooth and precise operation with minimal movement, and a universal joint that allows for flexible access to tight spaces. 

Ko-ken 72 Tooth Ratchets – Precision, Strength, and Control

Ko-ken ratchets are renowned for their precision engineering, delivering exceptionally low backlash, compact head sizes, and high torque performance. The newly designed 72 tooth ratchet continues this legacy, combining our hallmark features with refined advancements.

Featuring a patented dual pawl mechanism with a single spring, this ratchet provides a smooth 5° arc swing, allowing for superior control in tight spaces. The innovative design increases surface area contact within the gear, resulting in a 10% higher torque limit while preserving Ko-ken’s signature low-torque backlash performance.

After four years of intensive development and testing, we’ve optimized the spring pressure to maintain a consistent, precise feel with minimal resistance—perfect for professional users demanding accuracy and durability.