The result is a superior valve stem to keeper to retainer assembly.  When the fit is correct, there is no relative motion in the assembly.  This results in less wear and an extended service life of the components. 

Attributes of the lash caps include:

• ID control of 0.0004" (0.010mm) ' Tighter control is available upon request or if required
• Surface finish of Ra0.15micron ' Tighter control is available upon request or if required
• Crowned (domed) top surface available to insure center contact with actuating component
• Aerospace, through-hardened, medium-carbon steel for extended use and wear resistance

For the lash disk, the component should sit flat against the valve tip with good diameter and OD surface finish control to insure proper fit inside the retaining component.  Attributes of the lash disks include:

• OD control of 0.0004" (0.010mm) ' Tighter control is available upon request or if required
• Top and bottom surface finish of Ra0.15micron ' Tighter control is available upon request or if required
• Crowned (domed) top surface available to insure center contact with actuating component
• Aerospace, through-hardened, medium-carbon steel for extended use and wear resistance