tube bending,pipe bending,tube bending fabrication,exhaust tube bending,pipe bending fabrication,bent elbows,Woolf Aircraft Products

Tools for Mandrel Bending

Documents [new window]

Prebent Elbows Price List.pdf
Stock price lists for stainless steel, aluminum, and mild steel elbows, transitions, and straight tubing.

Request a Quote.pdf
Sketch an assembly and email or
fax your requests on this form

Elbows.pdf
Special angles or longer legs may use this form for single bends

Bend Die List.pdf
Bending Dies in stock at Woolf Aircraft arranged by tube diameter showing actual centerline| radii available

1. Mandrel - A solid cylinder that is sized to fit the inside of the tube to keep it round when bending. It is usually connected by links or cable to a series of segmented-machined balls that flex with the bend.

2. Bend Die - A rounded solid shaped cavity that accepts the tube, which is cut to a specific centerline radius. The outside edge is usually cut to one half of the tubing diameter. The pressure die and bend clamp dies then press the tube against it. While usually made out of hardened steel, they can be made from many materials including wood, plastic and aluminum. The bend die can be designed to produce a maximum of 180 degrees of bend.

3. Clamp Die - Usually a straight die with a half round groove cut in its face that matches with a second rounded half mounted in the bending die. The clamps press together to hold the outside of the tube as it is rotated in the die cavity. Normal clamp length is two times the diameter (a 2" diameter tube clamp would be 4" long). The clamps can be smooth, or may have grooves to help bite into the tube. In some cases they are made longer with soft faces to avoid marring polished tubing.

Close Tangent Clamps

4. Pressure Die - Similar to the clamp die, except much longer. Drag pulls it forward during bending and applies pressure against the back of the tubing as it is rotated in the stationary die. Many of our benders use a hydraulic cylinder to assist the motion of the pressure die to reduce drag on the tube.

5. Wiper Die - A half-rounded bar machined to fit on one end tightly against the bending die to keep pressure against the tube from the inside where the material is being compressed. It is used to avoid wrinkling the tube on the inside of the bend.

6. Close Tangent Clamps - Special Close Tangent Clamps are formed to fit the first bend and machined to fit the bend die. These specialized clamps allow bends to be located close together without welding. They are usually used for quantities of over 100 pieces.

Plug - A solid cylinder sized to fit the inside of the tube at the clamp die to provide a solid bite when clamping.