About Chamfer Dimension Schemes
Various attributes are used to create the chamfer geometry (chamfer pieces). These attributes include the chamfer dimension schemes. The dimension schemes enable you to easily define the chamfer plane angle and distance. Different dimension schemes result in different chamfer geometry. To simplify the chamfer creation process, the system uses a default dimension scheme. You can change the default scheme at any time in your design session to achieve the preferred chamfer geometry using the dimension scheme box on the Edge Chamfer tab.
Available dimension schemes
Dimension schemes are based on the placement references that you select and the chamfer creation method used. So, not all dimension schemes are available for a given geometry. The following dimension schemes are provided:
• D x D—Create a chamfer that is at a distance (D) from the edge along each surface. This is selected by default.
• D1 x D2—Create a chamfer at a distance (D1) from the selected edge along one surface and a distance (D2) from the selected edge along the other surface.
• Angle x D—Create a chamfer at a distance (D) from the selected edge along one adjacent surface at a specified angle (Angle) to that surface.
• 45 x D—Create a chamfer that is at an angle of 45° to both surfaces and a distance (D) from the edge along each surface. This scheme is available only for chamfers that use 90° surfaces.
• O x O—Create a chamfer that is at an offset distance (O) from the edge along each surface. This is selected by default only if D x D is not available. This scheme is only available if the Offset Surfaces creation method is used.
• O1 x O2—Create a chamfer at an offset distance (O1) from the selected edge along a surface and an offset distance (O2) from the selected edge along the other surface. This scheme is only available if the Offset Surfaces creation method is used.
Dimension schemes, relationship between surfaces, and creation method
Chamfer creation method

Angle between surfaces for chamfer creation

Constant 90° angle between surfaces 
Constant angle between surfaces, angle not 90° 
Variable angle between surfaces 
Offset surface

D x D, D1 x D2, Angle x D, 45 x D, O x O, O1 x O2

D x D, D1 x D2, Angle x D, O x O, O1 x O2

O x O, O1 x O2

Tangent distance

D x D, D1 x D2, Angle x D, 45 x D

D x D, D1 x D2, Angle x D

D x D, D1 x D2

Rules that govern dimension schemes
Chamfer dimension schemes define how the dimensions for chamfer geometry are calculated. In some cases, a set of rules limits the use of a specific dimension scheme. The system only checks these rules for the first selected reference in each set, and not for each edge in the chain.
The following rules determine which dimension schemes are available:
• Tangent distance chamfer creation method:
◦ D x D
◦ D1 x D2
◦ Angle x D—Surfaces with a constant angle between them
◦ 45 x D—Surfaces with a constant 90° angle between them
• Offset surfaces chamfer creation method:
◦ O x O
◦ O1 x O2
◦ D x D, D1 x D2, Angle x D—Surfaces with a constant angle between them
◦ 45 x D—Surfaces with a constant 90° angle between them