Custom Made Rollers — Precision Rollers

Cylinder / Roller

Straight precision rollers can be custom manufactured from a variety of materials. Rollers usually fall into two quality levels. Precision ground rollers are held to plus or minus two ten thousands of an inch tolerance on diameter ( ± 0.0002", .005 mm ) with a 6 micro inch "Ra" surface finish. Precision lapped rollers are held to plus or minus one ten thousands of an inch tolerance on diameter ( ± 0.0001", .0025 mm ) with a 2 microinch "Ra" surface finish.

We produce very high quality cylindrical bearing rollers and short cylindrical parts. Ground parts are typically held straight and round within .0001 of an inch with a 6 microinch finish. Size is held to a plus or minus of two ten thousands of an inch. If finer quality is required, the ground parts can be cylindrically lapped. After lapping typical parts are straight and round within fifty millionths of an inch with a 2 microinch finish. Size is held to a plus or minus .0001 of an inch.

We can produce parts that have a total quality envelope in the 2 micro inch range; but their cost is prohibitive for most applications. Rollers have some unique properties that must be identified. The information required on an order includes quantity, size, length and material. The standard roller bearing materials are chrome alloy steel, E52100, with a minimum hardness of 60 HRC or type 440c-hardened stainless steel at 58 HRC minimum.

  • Tolerances: What is the specific corner radius and tolerance required? The standard is de-burred with a slight radius. What is the length tolerance? The standard is ±.005".
  • How hard do you want it to be? The standard is full hard and stress relieved, (see above). Ends: Are the ends tapered, curved to a radius or just flat?
  • Do you require a squareness relationship between the outside diameter and the ends?
  • Must the ends be specifically parallel?

All rollers are custom made, so each order must be quoted.

Roller Type Diameter Round Length
Precision ground roller ± 0.0002"    
Precision lapped roller ± 0.0001" ± 0.00005" ± 0.005"
Straight Cylindrical Rollers ± 0.0002" ± 0.0001" ± 0.005"


Standard Dimensional Tolerance for Straight Cylindrical Rollers Lapped rollers with ground ends Ground rollers with machined ends
Roundness — 0.0001 inches. Diameter Size — ± 0.0001 inches. Diameter Size — ± 0.0002 inches.
Overall Length - ± .005 inches. Roundness — 0.00005 inches.  
  Overall Length - ± .005 inches.  

Questions to be answered for quotations on rollers.

  • What is the diameter?
  • What is the diameter tolerance? The standard is +-.0001”.
  • What is the material? The standard is chrome steel. (52100)
  • What is the corner radius?
  • What is the length?
  • What is the length tolerance?
  • Is a certain hardness required? The standard is 60 HRC. minimum
  • Are the ends flat or do they have a radius?
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