MIM

What Is MIM?
   Process Overview
When to Use MIM
   General Guidelines
   Technology Comparisons
   Materials Range
   Materials List
Design Guidelines
   Designing for Manufacturability
   Uniform Wall Thickness
   Thickness Transition
   Coring Holes
   Draft
   Ribs and Webs
   Fillets and Radii
   Threads
   Holes and Slots
   Undercuts
   Gating
   Parting Lines
   Decorative Features
   Sintering Support
Secondary Operations

Uniform Wall Thickness

Where feasible, walls should be of uniform thickness throughout.Variations in thickness lead to distortion, internal stresses, voids, cracking, and sink marks. In addition, they cause non-uniform shrinkage, interfering with dimensional and tolerance control. Thicknesses in the range 1.3–6.3 mm (0.05–0.25 in.) are preferred, but exceptions in both directions are possible.

Figure 1 shows several common ways to modify a form to achieve more uniform wall thicknesses. Removing material to create uniformity in wall thickness offers the added advantage of saving material; given the high cost of the very fine metal powders used in MIM, this can be a significant economic benefit.