ISO 8750 spiral pin, 4 x 18 mm, Article number 87500400187. Property class / material: steel, surface finish black oxide. Spiral Pin manufactured to ISO 8750. Standard parts to the same standard, property class, dimensions and surface finish are interchangeable between manufacturers; confirm the controlling standard revision, any class-society or application approval, and the mating thread before substitution. Applications: positioning, alignment and locking of machine elements, shafts and fittings in machine building, plant maintenance and marine equipment.