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Measure twice - cut once

Measuring tips:

Before you measure your Seconline security door, security window grill, or fly screen, always check your ruler/tape is reading a correct measurement. The way to do this is to compare it to a fixed steel or timber ruler. It is not uncommon for a brand new tape to measure up to 3 mm short or long. It is imperative that you are aware that you are measuring a true measurement.

  1. Always measure from the outside looking in. The reason we do this is to get the correct lock side.

  2. Measure several times and if you are not achieving the same specification then there is something incorrect with your technique.

  3. Use the deduction on the side of the tape block and do not bend the tape add this measurement back to gain the total overall measurement. This is a better or more accurate option than bending the tape.

  4. Have someone with you to assist in holding the tape and recording the measurements.

  5. Download measurement sheets from the website to take to the actual measurement site to write down all necessary specifications using the correct deductions supplied on the measurement sheet.

  6. There is a lot of useful information and videos to avail yourself of this information prior to taking any measurements; please read all information and watch all videos in our DIY Help Centre.

  7. During business hours we have an online chat service where you can ask questions, in addition to that you can email us at or simply call us on 1300 735 405.

  8. We give recommendations for the deductions, however, it is finished sizes that we need supplied. What you give us to the millimetre will be what you receive.

Seconline offer comprehensive measuring instructions for hinge doors, sliding doors, window screens, as well as hinged and sliding French doors. View our FAQ page for all your measuring instructions and videos.

Buy security doors online today and save hundreds. Good luck with your measuring!

Remember the old carpenters saying “Measure twice cut once”.  

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