Founded in 1958, Helical Lap is recognized as the premier producer of internal and external expanding cast iron cylindrical laps. In 1979 we became part of the Engis Corporation group of companies. Our ability to serve customers worldwide is facilitated through the Engis network of companies and distribution.Our range of standard and special I.D. and O.D. lapping tools are capable of producing mirror surface finishes with superior geometry to other finishing methods.There are many applications where Helical Cylindrical Lapping Tools can improve and correct imperfections in cylindrical geometry, for example: Barrel-shaped bores Improvement in straightness of I.D or O.D. Bell-mouthed bores Tapered I.D. or O.D. Out of round conditions; both I.D. and O.D. Cylindrical geometries that have been achieved with Helical Cylindrical Laps: .000005 (5 millionths) roundness .000010 (10 millionths) straightness Surface finishes better than one microinch Helical laps are simple to use and an economical solution for achieving precision finishes WITHOUT HAVING TO USE SPECIAL PURPOSE MACHINES