scope:

Purpose:

This specification is intended to serve as a guide for procurement specification preparation for any of a series of sheet and extrusion stretch-forming machines, including transverse and longitudinal, horizontal wrap, rotary, and s tretch-draw configurations. This standard lists minimum requirements and is not intended to limit design advances.

Classification:

The following types of sheet and extrusion (formed and extruded shapes) stretch-forming machines are presently in use within the aerospace industry.

Type:

I - Transverse:

Stretch-forming machine with sheet-jaw carriages transversely positionable during machine set-up and may or may not be positionable during period of stretch load application (forming). The die table may be tiltable in the vertical plane parallel to the sheet jaws.

II - Longitudinal:

Stretch-forming machine with jaw carriages longitudinally positionable during machine set-up. The tension cylinder provides necessary motion during the period of stretch load application (forming). The die table is generally tiltable in the vertical plane perpendicular to jaws. Multiple die tables may or may not be provided. The die tables may or may not act independently of one another.

III - Horizon tal Wrap:

This configuration is generally characterized as a stretch forming machine in which the part is formed around a stationary or moveable die in the horizontal plane. This type is notmally used to form extrusions (formed or extruded shapes), but may be used for sheet materials within limits.

IV - Rotary:

This configuration is generally characterized as a stretch forming machine on which continuous rotational forming is accomplished. A horizontal wiper ram is normally provided. This type of stretch forming machine may be used to form both extrusions (formed or extruded shapes) and sheet materials.

V - Stretc h-Draw:

This configuration is characterized as a longitudinal type stretch forming machine that combines function of stretch forming with press forming. The machine is generally used on parts that have flats, reverse contours, or indentations that require matched upper and lower dies.

Size:

Stretch forming machine size shall be a direct relationship of the maximum tension tonnage per side.

intended Use: