Formed Sleeves and Bushings

Hamond Industries Ltd - the Slide Forming Specialists


These cylinders were all formed at one to several parts a second from metal fed into the machine in strip form. The two on the left are inserted into clad metal wiring, the middle one is an anchor bolt sheath, and the one on the right is a bushing for a truck brake assembly.

One way to make a short tube is to extrude it and then cut it to length. But the cutting operation is problematic, for reasons of

Another method is roll forming the tube instead of extruding it and then contrinuous welding of the resulting seam. But unless the weld bead can be carefully controlled, you have dimension problems in the area of the weld seam. And you still have all the problems of cutting the tube of the above solution.

A third solution, the one we use, is to form a tube out of strip. We've done this for a number of applications:


Shaft Bushings

A formed steel bushing - also sometimes called a sleeve. We keep tight tolerances on both the I.D. and the O.D. and measure the insertion force into a bore gauge.

This is a plain formed tube. It may look simple, but the problem involves tight control over circularity, ID, OD, burr and gap size. Because of spring-back, the part cannot be made in a straightforward way. Our slide forming machines allow us to make the gap almost disappear. And the edges can have almost any kind of shape our customer desires.

A formed steel bushing being made. There are several ways to do this - the method shown here is the fastest and simplest.
A formed steel bushing or sleeve. We can hold tight tolerances on both the I.D. and the O.D. and measure the insertion force. Bushing being made. This video has been slowed - we can make approx 2 parts per second or 14 million per year per set of tools using this method. Other methods trade forming speed for accuracy.

Anchor Bolt Sheaths

Formed Anchor Bolt SheathHere we had to make a semi-tube, one that came apart at the far end and in a controlled way. There's also texture on the one end (those grooves) for a better grip.



Soft Steel Sleeve

This part is another formed sleeve, but this time with features, some of which go totally around the part and some only in certain areas. The video on the right is a smaller version of the one we use to illustrate how slide forming works.

Cookware

A heat shield (called a flame guard in our customers field). The part is cosmetic, so we formed it with special coated tools that don't mark the part.The tube is used as a heat shield (they call it a flame guard). The metal can be cut in a complex shape so that, when it is formed, it exactly touches the curved contour of the pot or pan and leaves no gap. Since both the pot and the handle may have arbitrary geometry, the resulting contour is not easy to calculate. Our software lets us do this with ease and our careful co-ordination with punch suppliers ensures that we get the contour we designed. Most often, for cookware, there can be no gap, so some sort of complete interlock is used, either by overfolding (there are 3 layers of material in a small area - this is sometimes called a "lock-seam") or else teeth are made in the strip before the tube is formed and folded into each other as part of the forming operation (so-called zig-zag seam).
In the picture, we used an interlocking tooth seam in thin stainless. The white stuff on top is plastic - we formed the part plastic coated and delivered it to the customer still coated. I've peeled away a bit of the plastic at the top so you can see the metal underneath.


Does any of this look like something you need? Give us a call or fill out our handy quoting form and we'll get back to you shortly.