This design standard specifies the dimensions of the externally threaded fitting end to be assembled into an internally threaded fluid system port, using an elastomeric o-ring for sealing. Fitting end dimensions and o-ring sizes agree with ISO 7320-1985.
This SAE Aerospace Standard (AS) provides general information for the interpretation and clarification of engineering drawing requirements relating to the manufacture and inspection of fluid system couplings, tube fittings, and hose ends. Because it is impractical to define every minute detail of the part on the face of the drawing, this standard describes interpretations of dimensioning of general machining features and otherwise undefined tolerances that fall under the heading of “good shop practice.” This standard is supplemental to ASME Y14.5M-1994 and explains, defines, and interprets drawing terms or practices that are not addressed by ASME Y14.5M-1994. Unless otherwise specified in this standard, drawing interpretations contained in ASME Y14.5M-1994 shall apply.
These formulae shall be used to determine drop dimensions for simple bend tube fittings utilizing flare and flareless end connection designs from 0° to 90° used in aircraft and aerospace applications. Individual design standards shall specify parameters, such as centerline bend radius (R), straight tangent length to accommodate bending equipment (X1 and X2), and nut to be used.