Roll Forming Spindle Reconditioning - Reconditioning Spindle Shafts Saves You Money
Before you buy new spindles, consider reconditioning the existing ones with hard chrome plating. Spindle reconditioning can be 25% less expensive than buying new ones made of standard pre-hardened or hardened materials. They are also guaranteed to last up to ten times longer.
Benefits of hard chrome plating of spindles:
- The plating is extremely hard, measuring 68-72 on the Rockwell C scale. Spindles are typically made of 4140 pre-hardened material which is 28-32 RC, or 8620 carburized and hardened which is 58-60 RC.
- The cost is generally about 20-25 % less than replacing the spindle with an 8620 carburized and hardened spindle, and about 20% less than a 4140 pre-hardened spindle.
- Lasts up to 10 times longer before the next reconditioning is required.
- Offers protection against corrosion and wear in tough environments, so roll tooling can easily be removed.
- Porosity and high lubricity combine to prevent excessive wear.
- Can be applied only to the specific areas that need to be repaired (so threads and keyways are not damaged) and the areas that do not need to be repaired are left untouched. This limits the overall amount of chrome that needs to be used, providing the most economical solution.
How do you know when it is time to have a spindle reconditioned?
- Do a visual inspection of the spindle’s surface. Look for pitting, wear marks, and grooves caused by oil seals.
- Check spindle diameters with a micrometer to ensure that the spindle is within acceptable dimensional tolerances. Industry standard for allowable undersize tolerance for the roll space portion of a spindle is .001” per 1.000” of the O.D. The diameter of bearing journals should be maintained within the manufacturer’s recommended tolerance for each specific bearing.
- Place the spindle in a vee block or between centers and using a dial indicator to check each diameter for runout. The amount of acceptable runout is application-specific; spindle diameter and material thickness are important factors. Runout has more effect on thinner material.
Hard chrome plating is not recommended when a needle bearing contacts the surface directly.
Author: Matt Hozjan, Equipment Assembly Supervisor