Duct bending tool

If workpiece cosmetics are important or the application has tight bending tolerances, the ram-type method may not be the best choice. Commonly used for large workpieces in construction, roll bending generally entails three rolls positioned in a pyramid, oriented either vertically or, for larger sections, horizontally. The rolls move to produce specific, usually very large radii.

Which rolls move where depends on the machine. On some, the top roll moves up and down to produce the desired angle; on others, the two bottom rolls move and the top roll remains stationary see Figure 5. Another machine type is the two-roll, pinch-style roll bender. For this system, the tube feeds between an upper and lower roll, while on either side two adjustable guides move to produce the desired bend angle.

Many use roll bending to produce spirals. If a workpiece has a one-diameter pitch and a large radius, the operator can lift the tube after one revolution to produce a continuous coil. Some applications, including those with a larger coil pitch, require an additional roll that guides the tube outward as the coil is being formed.

Compression bending uses a roller or compression die sometimes called a follow block to bend the workpiece around a stationary bend die Figure 6. The system clamps the workpiece just behind the rear tangent point. This method is most common in symmetrical workpieces—those with identical bends on either side—often bent in one setup on a machine with two bending heads. This method is used mostly to produce household and commercial products.

If you see a towel bar with two identical bends on each side, it was probably formed with compression bending see Figure 7. This process gives you maximum control over wall thinning and ovality. Rotary draw bending supports the flow of the material during bending using a mandrel in the tube ID and precision tooling on the outside see Figure 8.

Figure 2 A bend angle in tube bending usually is calculated from the outside—the complementary bend angle. Other critical dimensions are the wall thickness which thickens on the inside radius and thins on the outside radius and outside diameter. The pressure die also called a pressure slide supports the outside radius during bending.

All these elements effectively control both the tube ID and OD throughout bending. To achieve the perfect bend, you need a good tooling setup, and nowhere is this more critical than in rotary draw bending. Consider the mandrel—its hardness matters. If you have a hard tube and a hard mandrel, or a soft tube and soft mandrel, the mandrel will tend to stick inside the tube and wreak havoc on the process. As a rule of thumb, make sure you have a combination of hard and soft material.

If you have a hard workpiece, you need a soft mandrel; if you have a soft workpiece, you need to use a hard mandrel. Your tooling also should take radial growth into account see Figure 9. If radial growth is excessive, the nature of the rotary draw process means that after the clamp die releases, the radius at the beginning of the bend will be noticeably different from the radius at the end of the bend.

Draw bending also requires a good tube with good welds. Regarding the wiper die, its position is critical see Figure It should be sharp to the touch. The wiper die can wear over time, so for some jobs, it is good practice to keep a spare wiper die available. As for the clamping die, its length should be three times the tube diameter. The clamp die clamps the workpiece to the bend die and holds the tube as it is drawn around. The shorter the clamp is, the more pressure it puts on a short section of the workpiece, thus increasing the risk of deforming it.

This clamping die requirement can create challenges when you are forming a workpiece with short distances between bends, but special tooling can overcome this.

In this arrangement, you have a stack of two or three or even more clamp dies. One is a traditional clamp die used for holding straight sections, and the other—called a form die—is machined to a specific shape so it can clamp to previously formed bends. These advanced systems also can have stacks of bending dies for different tube radii, so an operator need not change out tooling between different jobs.

Certain tubes, especially those with thin walls, require a series of balls that can flex on the end of the mandrel, supporting the tube ID in the bend itself. The positioning of those balls matters during machine setup. Designed for cutting all types of hard and soft wood, and other non ferrous materials including plywood, composition board and siding. Use in any rotary or rotary percussion drilling device for unexcelled performance in brick, tile, granite, concrete, masonry and other similar hard and dense materials.

General purpose drills. A unique double flute design ensures the penetration of soft or thin materials at the proper speed. Fits cordless or corded drills. Durable elastic bands easily loop around motor housing for handy bit storage. Lightweight, compact size and slim nose projection allows this riveter to go wherever the work is. Malco blind rivets provide a strong, secure connection between 2 or more sheets of material, that will not loosen with vibration.

Solid carbide tip for scribing fine lines on hardened steel as well as glass, ceramics, plastics or sheet metal. Measure, mark and scribe trim lines on sheet metal in one easy operation. Set desired trim depth on scriber extension and tighten knob. Accurate and fast adjusting. Points are easily resharpened or replaced.

Nickel plated steel body. These distinctive blue chuck drivers withstand impact driver stress characteristic for each fastening application.

Use with wood, sheet metal or lag screws. Flexible anchor is ideal for masonry or stone. Lip on collar prevents anchor from pushing through hole in hollow walls. Kits contain equal quantities of anchors and screws with one matching carbide tipped drill bit. Use to scribe lines on metal, plastic and a variety of other materials. Pierce holes in wood, plastic, leather, — even light gauge metal. Two sizes handle a variety of layout applications.

Rugged, heavyweight nylon tool bag organizes large and small tools with ample capacity and multiple interior and exterior pockets. Heavy duty, crush proof tote trays are great for carrying hand tools and fasteners to the job site. Reciprocating saw blades for general purpose use. Malco offers a convenient pocket level for easy storage.

Built with a strong molded plastic frame with pocket clip. Join our mailing list. Submit Your Idea. Single Sheet Metal Crimper Fast, easy to use and lightweight. Handy lock makes tool pocket sized. Hand Seamers with Forged Jaws For bending metal and flattening seams, as well as straightening sheet metal or safely gripping and moving metal on the job. Portable Mini-Brake Makes bends to degrees in galvanized sheet steel up to 22 gauge 0.

Pan Style Mini-Brake Fabricate pans and boxes, flashing and fascia corners, plus large metal duct, and roofing components on the job. Aviation Snips — Left Cutting and Right Cutting Vertical Left-cutting and right-cutting forged steel jaws are set at a degree angle to allow easy gripping when cutting sheet metal in tight spaces or overhead. Forged Steel Snips Forged steel snips for cutting straight, wide curves, and notches.

Hole Punch — Sheet Metal, Vinyl Plastic Use for edge hole applications in sheet metal or vinyl plastic including metal ductwork and vinyl window extrusions.

Snap Lock Punch for Sheet Metal Raises a projection along edge of sheet metal for locking into rolled edge of sheet to be joined. Bend more than one size of tubing without adjusting the bending head. Powerful enough to bend conduit and pipe to the angle you need with one stroke of the pump, these are for use on Schedule 40 pipe.

Heat PVC conduit and pipe, then manually bend it to your desired angle. Make on-the-fly bends in Schedule 40 PVC conduit and pipe without the risk of kinks or cracks. Lightweight and flexible, these benders are easy to keep on hand for occasional use and last-minute adjustments. Follow the easy-to-read markings to bend conduit to the angle you need. Choose these benders for short-radius conduit bending.

When you're working with exposed conduit, these benders make offset bends so your conduit matches knockout holes in electrical boxes.

Create smooth, accurate bends in round heat pipe for routing heat away from sensitive electronic components and toward a heat sink.

Create squares, coils, and S- shapes. Pull coiled tubing through these straighteners to make it smooth and level. Repair ends of thin-wall EMT conduit that have been warped by cutting.

System of Measurement. For Tube OD. For Use On. Bend Radius. Maximum Bending Angle. Power Source. Angle Increments. Mandrel Material. For Pipe Size. For Rigid Conduit Trade Size.