Shock absorbers
Low friction. Less wear. Less leakage.
TripleHard® on shock absorber rods: less sliding wear than Cr(VI) hard chrome at the same thickness, lower friction against the seal, and lower seal leakage than the Cr(VI) reference in a 250,000-cycle test by a global OEM. Made in a Cr(III) hard-chrome process.
- 4×
- less sliding wear than hard chrome on the same shaft at 15 µm
- 250k
- cycles in a global OEM's seal test: lower leakage than the Cr(VI) reference
- 1 275 lbf
- block-on-ring load without galling; hard chrome galled at 1 125 lbf
Why shock absorbers
The rod that never stops moving.
A damper rod strokes through its seal continuously, under side load, in road grit and salt. Friction, wear and seal life decide how long the damper feels new.
- Galling resistance. Carried the full block-on-ring load where hard chrome failed
- Wear. Half the Taber wear of hard chrome; a quarter in sliding wear
- The seal. Lower seal leakage than the Cr(VI) reference in a 250,000-cycle test by a global OEM
- Corrosion. Rating 10 at 1000 h in neutral salt spray, depending on the nickel underlayer
How it is produced
On a converted line.
Current TripleHard® has been tested for shock absorber rods. Each customer application is engineered from the customer's drawings and verified during commissioning. The results on this page are from tests on shock absorber rods.
Shock absorber rods are plated on your existing line, converted to TripleHard®: the chemistry, the anodes and the process control change, and fume scrubbers are no longer needed. Savroc supplies the process, the chemistry and the support.
Read the technology page How a project works- Changes in a conversion
- Carries over from the existing line
- Carries overHoist and railThe existing hoist carries the part from tank to tank.
- Carries over1 · Surface preparationCleaning, as on the existing line.
- Carries over2 · EtchingActivates the steel surface, as on the existing line.
- Changes3 · Nickel anchor layerA nickel bath is added where the line has none.
- Changes4 · TripleHard® Cr(III) bathReplaces the Cr(VI) bath. Anodes change to graphite or Ti-MMO. Ordinary lip extraction, no scrubber.
- Carries overRinses and rectifierThe rinse after each stage and the rectifier stay as they are.
Technical package
What is measured.
Full test conditions and the regulatory position are on the technology page.
| Galling (block-on-ring) | Step loading over 3 200 s: no galling up to the maximum 1 275 lbf (about 850 MPa); the Cr(VI) reference galled at 1 125 lbf |
|---|---|
| Abrasion (Taber) | CS-10, 1 000 cycles, 1 kg: 1.03 mg against 2.0 mg |
| Sliding wear | A quarter of the wear depth of hard chrome on the same shaft at 15 µm (case study) |
| Seal leakage | In a 250,000-cycle test performed by a global OEM, TripleHard® showed lower seal leakage than the Cr(VI) reference |
| Corrosion | NSS (ISO 9227): rating 10 at 1000 h, and at 250 and 500 h; depends on the nickel underlayer. AASS 96 h at 15 µm (case study) |
Frequently asked questions
How was the block-on-ring test run?
A coated ring ran against a carburised steel block, grease-lubricated at room temperature and constant speed, with the load stepped from 50 to 1 275 lbf. A Cr(VI) hard chrome ring ran under the same conditions as the reference. The report is on the technology page, under Documentation.
Does lower friction change the damping?
It removes friction the damper was never designed around. Damping stays where the valving puts it, and the seal sees less heat and wear.
Can I run it on my existing line?
Yes. Shock absorber rods are coated on a converted line; most infrastructure carries over. The continuous line is for hydraulic cylinder rods.
Ready to start your move off hexavalent chromium?
Send us your drawings and the conditions your parts work in. We simulate the coating on your parts, design the line or the conversion with you and stay through commissioning in your plant.
Start your project with Savroc