Mandrel Tube Bender

It is widely recognised when bending tubing that the normal minimum bend radius is 4 times tube diameter. Attempting to bend on a smaller radius introduces a number of problems, namely rippling on the inside of the bend, cracking or splitting on the outside and extreme distortion of the tube

For those who need a tighter bend radius we have designed the Useful-Tools hand operated mandrel tube bender. These machines will allow tubes to be bent with an impressive 2 times tube diameter bend radius with no rippling or cracking of the tube and the absolute minimum of distortion.

We have 2 machines that all operate on the same principle, namely the pipe or tube to be bent is located between a formed mandrel and back plate with another formed internal mandrel (bullet) held at a carefully controlled position inside the tube.

The tube is secured firmly to the main mandrel and when the mandrel is turned the tube is pulled over the internal mandrel as it wraps around the main mandrel.

(This internal "Bullet" holds the tube open and helps reduce distortion to a minimum.)

The MK 3 Bender will bend up to 3/4" diameter in steel as well as all the following sizes of aluminium:

  • 3/8" dia. on a 1.0" centre line radius
  • 1/2" dia. on a 1.0" or 1.5" centre line radius
  • 5/8" dia. on a 1.25" or 1.5" centre line radius
  • 3/4" dia. on a 1.5" or 2.0" centre line radius
  • 7/8" dia. on a 2.0" centre line radius
  • 1.0" dia. on a 2.0" centre line radius
  • 1.125" dia. on a 2.5" centre line radius
  • 1.25" dia. on a 2.5" centre line radius
  • 1.375" dia. on a 2.5" centre line radius


We can supply machines that will bend from ¼" diameter up to 1.5" diameter, all on a 2 times tube diameter bend radius.

We carry a large range of mandrel sizes and can cater for millimetre and special sizes.

Check out the attached video showing how easy the machine is to use:

MK 5 Bender (5-1)

Because of the sheer physical effort involved in bending 1.0" x 16 swg steel we designed a machine that we call the MK 5 5-1.

This machine has a five to one reduction ratio between the operating spindle and the main mandrel spindle, which means we can now bend stronger and larger tube than on the Mk 3.

This machine retains all the standard features of the Mk 3 machine and is the most versatile machine in the range, able to bend pipes ranging in size from 3/8" diameter all the way up to 1.0" in stainless steel, and 1.5" in aluminium and copper.

The Mk 5 can bend 1" x 16 swg stainless steel tube on a 2.0" Centre Line Radius - whether solid drawn or electrically welded.

There are a few differences from the Mk 3:

* Mandrel is now driven by two 8mm dowels instead of a 5mm key

* The base plate is larger to allow the use of larger size mandrels

* There is an additional support roller for the back plate to stop flexing

* 5-1 built-in reduction ratio

(The MK 4 bender has now been superceeded by the MK 5 - which can do all the MK 4 could and so much more - and so is no longer available.)

We also do a stretched version of the Mk 5 bender for larger centre line Radius mandrel bends.
In most cases, a thinner wall tube can be bent very satisfactorily and we can provide internal 'bullet'-type mandrels to suit your tube wall thickness requirements.

Due to the unique design, the Useful Tools Tube Benders will allow amazingly tight bends to be formed with the minimum of tube distortion (a nominal 3-4%).

The Tube Benders come with an easy-to-read degree dial to allow precise angles of bend to be achieved and repeated.
The machines are extremely easy to use and allow for multiple bends in the same piece of tube at alternate angles on different planes. Once the machines are set for a particular size of tube it will be found that multiple bends are rapidly achieved.

Check out the sample pictures of the 5/8" and 3/4" od tubing bent on a 1.5" CLR, and the 1.0" steel and stainless steel tube bent on a 2.0" CLR.

Please remember to select the mandrel(s) you require when ordering.

Click on the following videos to see how easy it is to produce really tight bends:
1/2" x 1" clr
3/4" x 1" clr
1" x 1.5" clr

The mandrel price includes:

Basic mandrel
Internal mandrel

Formed backing plate
Tube clamping plate


If you have any special requirements, please email us:

Mk 3 Bender: £375MK 5 Bender: £595

+ VAT @ 20% where appropriate

To allow us to provide the correct internal mandrel, please specify the
internal diameter (ID) of the tube to be bent in the box below.

VAT may be applicable to this transaction

Basic machine price (no mandrel)
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Please specify the ID of the tube(s) to be bent
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