ISMT Limited supplies Smooth Bore Tube for Piston Pins. ISMT Limited manufactures a wide range of precision seamless tubes and alloy steel tubular products for the Bearing, Automotive, Mining, General Engineering and Energy sectors. The Smooth Bore Tube for Piston Pins is a cold drawn with a mirror finish on the inner diameter so as to achieve a Ra value of as low as 0.5. The Smooth Bore Tube for Piston Pins is made from seamless tubes to provide a cost effective alternative to piston pins made either by forging or by machining solid bar stock.