Flattening tube ends.

[Mark P.Participant @markp]

Hello all.What will be the best way to flatten the ends of some 3/8" dia stainless tube to create something similar to this photo?Would I be best off making a die to do the job,I have tried squashing it in a vise but the results were not satisfactory.They are for mudguard stays on a motorbike so they will be on show,and a good finish is required.

Regards

Mark P.

[Mark P.Participant @markp]

[SteveWParticipant @stevew54046]

I think I'd take two short bits of angle and file a radius in the top corner. Then use them in the vice. I think you will need to experiment with a more gradual radius to get the effect you want. The bits of angle would only have to be a bit longer than the tube diameter so not very wasteful.

As it's in stainless ….good luck!

Steve w

[Gordon WParticipant @gordonw]

Fit a suitable size of flat bar in each end, I suppose s/steel for your app. The size of bar can be found by trial and error, there is somewhere a formula for doing this but can't find it, sorry. This is the usual way to do this PS use smooth vice jaws.

[JAParticipant @ja]

Many years ago, as a student, I had to flatten stainless hypodermic tube in a similar manner many times. When the tube was annealed there were no problems, You will need to experiment but heat to a good red heat and cool as slow as possible.

JA

[thomas oliver 2Participant @thomasoliver2]

I formed the ends on some mudgaurd stays years ago and probably still have the formers. It is necessary to form a rounded end to the main tube not a squared off one , as would be obtained simply by squeezing between the vice jaws. If I remember. I made two half formers by driiling down a length of square bar, which was then sawn down in half. I then used a ball ended cutter to form the hemi spherical ends. Then the cavities were extended with a milling cutter to accomodate the flattened end. It is best tor remove all sharp corners slightly with a file. A heavy vice was used to apply the pressure. I remember that it did an entirely neat and satisfactory job.

[Mark P.Participant @markp]

Thanks for the replies,job now sorted.

Regards Mark P.

[Sub MandrelParticipant @submandrel]

I see the job is now done, but just for reference, I had to re-bend a mooring hook in 1/2" stainless steel. Heated to a red heat I was able to bend it by hand with one end in the bench vice.

Neil

[ChrisHParticipant @chrish]

Beware of rearranging stainless steel with a hammer to get the flats – stainless gets brittle when hit and can then fracture.

ChrisH

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