unfavourablefavourable

• Provide taper with
  b 0.005 h to ease removal from the mould
  (not necessary for isostatic pressing and extrusion)
  

           unfavourablefavourable

• leave countersinks open to the edge (crack prevention)

           unfavourablefavourable

• select a sufficiently large edge clearance for holes
  
• Ratio s/h
  
  
  Examples:
  

         unfavourablefavourable

• avoid protruding details with a small cross-sections

           unfavourablefavourable

• limit the height of parts that are uniaxially pressed
  
  

  h/d < 6	possible
  h/d < 3	favourable

• ensuring minimum wall thickness
  
  

  h/s > 8

  Extrusion or isostatic pressing

           unfavourablefavourable

• lateral holes should not intersect
  
• avoid lateral holes
  

           unfavourablefavourable

• ensure technically practicable parallelism

           unfavourablefavourable

• Angled parts should have thick arms, minimised finishing surfaces and
  well-defined mounting areas
  

           unfavourablefavourable

• Avoid tapered shapes (cylindrical ends result in good edges and
  reduced tool wear)
  

           unfavourablefavourable

• Sharp (or feather-) edged dies that may meet during pressing are unusable, add a small cylindrical section with a small end region

           unfavourablefavourable

• shallow inclines, or none at all, yield denser microstructures

           unfavourablefavourable

• avoid sharp internal corners

         unfavourablefavourable

• avoid rounded edges or edges with acute angles

           unfavourablefavourable

• avoid sharp corners and edges at the
  intersection of
  lands and ribs
  (risk of cracking and liability to fracture)
  

          unfavourablefavourable

• avoid flat bottoms
  in blind holes
  (overpressing)
  

          unfavourablefavourable

• reduce upper countersink depth and allow sufficient wall thicknesses to result in lands without cracks and a more uniform density

           unfavourablefavourable

• avoid overpressing flanges, keep press depth from the top small in order to achieve a uniform
  density
  

          unfavourablefavourable

• run lateral undercuts (internal and external) to the top
  

           unfavourablefavourable

• rounded or bevelled edges are easier to
  demould; keep bottom thicknesses large; keep depression ‘a’ on the top face if possible to only 0.5 to 1 mm deep
  

         unfavourablefavourable

• incline transitions wherever possible

 
           unfavourablefavourable

• move lateral holes into the upper region of the part
  (easier manufacture using a bar)
  

         unfavourablefavourable

• Avoid thin free-standing walls
  (danger of distortion)
  

           unfavourablefavourable

• non-uniform material distribution and
  excessively thin walls lead to cracks
  

           unfavourablefavourable

• avoid sharp outer edges

           unfavourablefavourable

• rounding prevents cracks and spalling

         unfavourablefavourable

• provide flat surfaces to avoid the need for
  custom-made
  kiln furniture
  
• avoid offset and
  relatively small
  mounting surfaces
  

         unfavourablefavourable

• keep support points close together
  (risk of warping)
  

           unfavourablefavourable

• provide channels to accept the glaze

           unfavourablefavourable

• attempt to keep
  support or mounting points free from glaze