A 6M 7M12 Ultra-Miniature Chain Drives
A series of ultra-miniature 3.117-mm (0.12 in.) pitch molded chain drives are designed for use where limited space and weight factors are important. They are used in communication equipment, business machines, cameras, and other electronic or electro-mechanical devices.
Made of pre-lubricated, non-magnetic black acetal, these drives—identified as the A 6M 7M12 series—are designed to operate over a wide range of temperatures from -40 to 121°C. The chain features a unit-link design that eliminates the need for a master link. Each unit-link measures 2.08-mm (0.1 in.) high and 4.12-mm (0.2 in.) wide. A length of 321 links snapped together will equal 3 ft (1 m) and a length of 16 ft (5 m) of chain weighs only 0.07 lb. (0.031 kg). Chain operating speeds of up to 16.7 in./sec (5.1 m/sec), around smaller 8-tooth sprockets, and maximum operating loads of up to 2 lb. (0.9 kg) of tension are recommended.
The A 6M 7M12 sprockets are stocked in 14 sizes from 8 through 48 teeth. Three bore sizes are stocked for press-fitting the sprockets to 3, 4, and 6-mm (0.12, 0.16, and 0.24 in.) shafts. Sprockets that have 24 or more teeth are molded with a spoked configuration. Outer diameters range from 9.4 to 49.3 mm (0.37 to 1.94 in.) and pitch diameters from 8.1 to 47.4 mm (0.32 to 1.87 in.).