Spring-Type Slotted Straight Pin M2.5 x 12 mm T301 Stainless Steel T301 Stainless Steel is an austenitic stainless steel with a nominal composition of 17 percent chromium and 7 percent nickel, which provides good strength and ductility when cold worked. It is a little less resistant to rust than T304 and more likely to be magnetised after cold working. Spring-Type Slotted Straight Pins (Roll Pins). ISO 8752 [REPLACES DIN 1481]. Spring pins are a very reliable low cost fastening system. Manufactured to a diameter greater than the drilled hole into which it is pressed. The purpose of the slot in the pin is to allow compression when inserted in the hole. The outward spring forces act positively in preventing loosening by vibration. Typical applications use spring pins as Fasteners to secure handles and gears to shafts, Retaining pins, Axle shafts, Stop pins, Hinge and pivot applications, Cross bars, Tube reinforcing pins, Locator pins Dimensions: "M" Size a d(min) d2 l M2.5 0.4 2.8 1.8