In order to avoid confusion with regards to the many ways of measuring the OK dinghy masts here you will find a few tips and pointers.
The bend numbers that Ceilidh Composite Technologies provides are measured with a 10kg weight placed at the top of the mast.
The length of the mast from deck (Mast Datum Point) to the absolute foot is 495mm. This length is called the mast bury. If your mast bury is shorter than this it means that the mast tip deflection will be less. Typically a 40mm shorter ‘bury’ results in 10mm stiffer tip fore-aft and 5mm stiffer tip sideways. The length of the ‘bury’ does not influence the bend curve of the mast itself.
When providing the measurements of the mast for us to finish the mast please provide us with the diameter of the deck ring (accurate to 0,1mm), the diameter of the mast foot (accurate to 0,1mm), and the length from the top of the deck ring to the bottom of the mast ( accurate to 1mm). If you are unsure of what to measure please look at the photos on this page kindly provided by Ralf Tietje (GER-787).
Typical dimensions for different hulls are as follows.
Strandberg Marine, deck 96mm, foot 75mm, bury 460mm (standardized in 2015)
Woody (NL) , deck 98mm, foot 76mm, bury 485mm
Idol Composites, deck 96mm, foot 76mm, bury 460mm
The masts are provided with halyard, gooseneck and cross bolt in the gooseneck however without a boom bolt. Each mast is measured at our factory and corrector weights are applied as and when required