Do not bend Bendywood handrails directly on the railing!
Pre-bend the handrails on a template and over-bend them by approximately 30%!

You can find the instructions at the following link:
How are handrails bent against a template?

How tightly can handrails be bent? 

Bendywood® handrails joint lengthwise can be bent up to radius of 20 times the
profile cross-section, e.g., a 40 mm round profile up to a radius of 800 mm. 

If tighter radii need to be bent, there are 3 options: 

   1. bend the profile vertically halved with tongue and groove 
       This allows the Ø 40 mm profile to be bent up to a radius of 400 mm. 

You can see an example of how this works at the following link:
   Bendywood Sofa by Flore André from Ø 42 mm cut in 2 halves bent up to R40 cm

    2.  bend the profile in 4 sections using tongue and groove joints:
         this means the Ø 40 mm profile can be bent to a radius of 200 mm, even in 3D!

For examples please see at the following link:
Tight 3D curves with Ø 40 mm split into 4 parts Bendywood

3. bend the profile cut into laminations:
       this means the Ø 40 mm profile can be bent up to up to R55 mm,
       as described in the following link:
            Bendywood short radius bent handrail parts 

Back to the topic of how handrails are bent:

In order to be able to bend up to these limits a wood moisture content of about 12% is indispensable.
See part 2. How to bend and moisten Bendywood®.

Bendywood® handrails are delivered with a wood moisture level of approx. 12%.
Handrails must not be bent immediately: packaged wooden moisture last for a good 2 months.
The handrails should only be unpacked just before you start bending.

ATTENTION:
The pre-bent handrails open up when removed from the template: they have been "over-bent,"
that is, bent with smaller bending radii to compensate for this opening.
See the following link: “Spring-back after being taken from the mould”.

The available Bendywood® handrails are shown in the catalog, see under: Catalogue
The pliable handrails are:

• made of solid hardwood
• pre-profiled, roughly sanded
• with 12% wood moisture, ready for bending

BENDING JUST BY HAND:

a. Bending an ascending handrail around a flat mould:
    this is the easiest and best solution for spiral staircases!

    The handrails with normal joints  are also well suited for this 

    See video for a round handrail:

    See video for a round handrail with flat bottom side:


    PARTICULARLY IMPORTANT:

1. Always bend around a mould - as shown in the videos

2. Position the matching bend mould / chunks for pressing exactly opposite to the joint
      

3. Ascending handrails should be pre-bent around a flat mould. Only after approx. 24 hours the 3D bending can be carried out at the banister.

    The following video shows how such a handrail is installed upwards:

 
    The flat pre-bending has the following advantages:

    - The transport costs are significantly lower than the costs for shipping long straight sections.
    - It is possible to perform the upwards bending later, when mounting the bending handrail.
    - It is also possible to combine normal wood with Bendywood®.
    - Also lengths up to 12 m are feasible, as special production.
    - Handrails with groove/plow are also possible.

b. Bending an ascending handrail around an ascending mould / assembly support:

When flat pre-bending is not possible, for example with steeply rising handrails and when 3D pre-bending
is required, special templates are needed for this purpose.
You can find illustrations of these at: Bending moulds for Bendywood®

BENDING BY USING A RING ROLLING BENDING MACHINE: 

• Solely the bending handrails with diagonal joints can be pre-bent with a ring rolling bending machine (up to a radius of 1 : 30), as only diagonal joints can endure the mechanical stress of a bending machine. A handrail with a diameter of 40 mm, for instance, can be bent up to a radius of 1.200 mm. The final bending - if necessary - up to a radius of 1 : 20 should be carried out by hand around a mould or on the banister. See the following video to this:  

• Tighten the bending radius progressively, letting the handrail run through the rollers of the bending machine not more than 3 times. Bear in mind that the ring rolling bending machine also rolls the wood and rolled Bendywood® will reach its limit of flexibility more quickly. Consequently, a 40 mm thick handrail, for instance, can only be bent up to a radius of  1.200 mm by machine, then you should continue by hand.       
  
  
• The bending handrails with normal joints CANNOT be bent with a ring rolling bending machine.

HOW TO BEND NON-ROUND HANDRAILS UPWARDS ?

All handrails turn on their own axis when being bent upwards. This torsion is not visible in case of a round handrail, as a round profile always looks the same when turned. In case of other profiles or round profiles with a groove/plow it is necessary to compensate for torsion, so that the lower part of the handrail remains below.

It is best to proceed as follows: (in one operation cycle)

First of all bend the handrail on a flat mould. Then clamp it onto the banister (which ideally has a flat steel strip or similar) starting from above. The "turning" should be carried out using a long-arm clamp, which needs to be clamped onto the handrail at a distance of 1,5 m in order to have sufficient leverage. 

FORMULA FOR CALCULATING THE LENGTH OF A SPIRAL STAIRCASE HANDRAIL:

EXAMPLE:

Assuming:

• 18 steps
• Step rise: 17 cm
• Step run beneath inner handrail: 13 cm
• Step run beneath outer handrail: 40 cm

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