It is the main component of all connectors and other parts to its Assembly. It resolution appearance of connector, need to acknowledge its structural strength to accept the end user damage to normal operation or customer specified testing standards (for example: request the force exerted in all directions to an external cable, cannot see the damage; or when the device screw, applying proper torque can not form). Since it is a body member, natural to assume duties of each orientation of parts, thus with other parts of matching parts of the scale and the public service (including public service) need to know what is appropriate. The main feature (for example: device terminal hole the drawer width) single mold if resolution of its scale, and the mold can be manufactured by grinding, you can set the scale of public-service +/-0.02 mm to ensure the function. Others such as position, flatness, general public service, such as to proper use, ensures that the function.