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Published: 05/10/2018

How to Cut Stainless Steel Trunking and Fit a Coupling

During the installation of Stainless Steel Trunking, it may be necessary to cut the product to comply with fitting restrictions. This is a simple process which can be carried out on-site. To cut Stainless Steel Trunking, the following tools may be required:
  • Hacksaw
  • Vice
  • Cutting fluid – ROCOL
  • Tape Measure
  • Screwdriver
  • Pencil
  • Power Drill
  • A high quality Drill Bit
  • Coupling Kit
  • Spanner
  • Sandpaper
  • Eye Protection
  • Gloves


It is important to note the following instructions are for guidance purposes only.

Cutting a length of Stainless Steel Trunking

In order to successfully cut Stainless Steel Trunking:
  1. Hold the trunking securely in a vice.
  2. Using a tape measure and pencil, mark the trunking at the required length.
  3. Put on your Eye Protection & Gloves.
  4. Using a hacksaw and copious amounts of cutting fluid, cut the trunking taking long slow strokes to prevent the build up of heat due to friction.
  5. Remove any burrs caused by the cutting with sandpaper to reduce the risk of personal injury and damage to cables.


This technique applies to both the base and lid of the Trunking.

Drilling the coupling & lid fixing holes

Once the trunking lid and base have been cut, new holes will need to be drilled to accommodate a new flat lid trunking coupling kit or, in the case of 15° Apex Lid Trunking, a 15° apex lid trunking coupling kit and lid fixings, in order to continue the flow of the trunking system:
  1. Mark the trunking where the coupling holes (to suit M6 fixings) are required.
  2. Using a power drill at a slow speed, with copious amounts of cutting fluid, drill through the trunking.
  3. Remove any burrs once the trunking has been drilled. This will reduce the risk of personal injury and damage to cables.


Repeat the above process to drill the 8.5 mm ∅ lid fixing hole(s) which should be situated 19.0 mm (centres) from the end of the lid.

It is important to note that if a high drill speed were used the Stainless Steel would overheat, causing it to harden and making it difficult to re-drill. It would also change the appearance of the steel and could damage the drill bit.

An additional coupling kit would need to be purchased in order to continue the flow of the trunking system once it has been cut. Our coupling kits comprise of:
  • 1 x coupling with nuts and screws
  • 1 x patented cover plate
  • TB1 or TB2 turnbuckles to suit the size of the trunking length
Coupling kits are used to join two pieces of trunking together. The U-shaped coupler is placed inside the trunking, across the join, and secured with the screws and nuts provided. For your reference, coupling holes should be 7.5 mm ∅ and 22.0 mm from the end of the base. 

If you require any more information to assist you with all aspects of your installation, please don’t hesitate to contact us.