3.5.4.4 Design Rules for Parts Made From Rolled Rings

1. To minimize stock allowances, indicate which surfaces may be left as forged.
2. Inside and outside contours are possible where required. See Section 5.2.3 for common contours.
3. Modern ring rolling mills are able to control one of the diameters (either the inside or the outside) more closely than the other. Therefore, indicate the chucking diameter for the first machining operation so that the supplier may produce rings with better consistency in the specified dimension, saving machining setup time.
4. Always specify finish machined dimensions; finish allowances may vary among ring rollers based on individual capabilities. (See Figure 3-21)
5. Supply the drawing, even when purchased quantities are low. Sometimes existing tooling and geometry will fit the requirements.
6. Specify the type and location of required identification, which will be stamped into the ring.
7. Avoid specifying close tolerances and fine surface finish on rough turned rings. Usually a ±1.6 mm (0.062 in.) tolerance and 6.3 micron (250 micro inch) finish are practical.
   
   
   

   Figure 3-21 specify finish dimensions and allow the ring rolling source to determine the finish allowance.

8. For addition information see Appendix C Tolerances for Rolled Ring Forgings.