April 2013: How it’s Made

KYB’s Shock & Strut Piston Shafts

Many thousands are manufactured every day and in KYB facilities all around the world: KYB hardens, cuts, machines, cleans, chromes, grinds, buffs and inspects our piston shafts dozens of times to be 100% sure that every shock and strut shaft is the smoothest possible and imperfection free. That’s what it takes to earn our brand reputation: Original Equipment for the Aftermarket.

The highest quality finished piston rod is essential to any shock or strut. Why? A shock or strut shaft will cycle up or down as much as 75 million times during 50,000 miles (80,000km). Any imperfection on the polished shaft will prematurely wear the upper oil seal and cause a leak… destroying the unit.

To make a great piston shaft, you need to start with great material. KYB piston shafts arrive as raw bar stock made to the specific steel quality & size requirements of KYB Engineers.



From here the raw bar stock rods are sent through a high temperature metal hardening process to add strength.


Next the bars are auto-fed into a CNC (computer numerical control) machine that will cut them down to size, and machine the bar ends into shaft shoulders & threads.



Grinding then brings the shaft diameter down to the correct size. It is a very thorough and exacting process with each shafts’ outer diameter hand checked as it finishes the grinding process.



There will still be some micro-small pores in the metal so they pass through a cleaning process prior to chrome plating. The shafts are loaded onto an automated dipping machine, 60 pieces at a time. KYB piston shafts will go through this process three times to achieve our triple chrome plated finish.



After chroming the piston shafts travel along a conveyor and through a laser scanning micrometer to check for metal inclusions that couldn’t be seen by the human eye and to insure that every shaft is the precise diameter.



The last machining step is the buffing machine that will leave the surface polished smoother than glass. But, we’re still not done. From there every shaft receives a final inspection under specialized lighting before being placed in trays and sent to the final assembly lines.



The result is an ultra-smooth, ultra-strong KYB piston shaft that won’t wear the oil seal and won’t let you down. From start to finish each KYB piston shaft is quality-proven up to 20 times before we will use it in a KYB shock or strut. That’s OEA quality: Original Equipment for the Aftermarket.



Find the Nearest Shop/Installer

Locate a KYB Certified Ride Control Center in Your Area go!