Shakti Springs Inc. Manufactures Spring Dowel Sleeves and Pins. Shakti Springs Inc. Is an ISO 9001 certified company. The Spring Dowel Sleeves and Pins are manufactured in accordance to IS 8351/IS 5988 [Light and Heavy Patterns]. The Pin is readily available in metric lengths ranging from 25- to 127- mm, and from 5- to 12- mm in diameter. The Spring Dowel Sleeves and Pins are widely used in Auto Industry, Electrical Industries, Electronics, Chemical Industries, Railways, etc.