Alloy round, mast tube - 11.0 mm (7/16 in) Ø
Details
Alloy round, 11.0 mm (7/16 in) Ø
7075 alloy T6 hardness. Identified by a non-tamper sticker to aid the measurement process. 54 grams/metre. Choose length and colour.
Both ends of 1800 mm pieces may be distorted in section and have marks where electrical attachments are made for the anodising process. About 15 mm are affected.
Pre-bend can be added to the mast if you wish. And the holes for spreaders, shrouds and forestay can be drilled and sail limit marks applied too.
SAILSetc supplies a large number of co-ordinated fittings that work well with this spar material.
It is costly to send full length pieces so consider having several pieces and split the cost with others. It is more economical to send 0.9 metre (or shorter) lengths and masts may be made using joint piece, ref. 17-110. Either add the joiner here or order it from the mast fittings section of this website.
Graphs of 'Stiffness of mast spar material against diameter' and 'Stiffness of mast spar material against weight/metre' are shown in the thumbnail sketches. The suitability of any SAILSetc mast spar material for its intended application can be checked using the graphs shown in the FAQs section - link.
These tubes are very difficult to pre-bend. To help add the bend we have developed a special tool - here.
To help drill accurately aligned holes in the mast spar we have developed mast drill blocks - here.
Guidance on pens suitable for marking difficult surfaces - here.
Suggested pre-bend
The level of pre-bend suggested by different designers is listed here for guidance. The mast deflection is the distance from the top of the mast to a straight line through the lower section of the mast. The distance from the top of the mast over which the bend is applied is given too.
rig | deflection | over upper | |
designer 1 | 1 | 8 | 650 |
2 | 5 | 600 | |
3 | 0 | 550 | |
designer 2 | 1 | 13 | 1060 |
2 | 10 | 840 | |
3 | 10 | 620 | |
designer 3 | 1 | 14 to 16 | 600 |
2 | 6 to 8 | 400 | |
3 | 0 | 600 | |
designer 4 | 1 | 15 | 600 |
2 | 7 | 400 | |
3 | 0 | 200 | |
designer 5 | 1 | 30 | 1350 |
2 | 12 | 950 | |
3 | 0 | 500 | |
designer 6 | 1 | 40 | 1070 |
2 | 25 | 790 | |
3 | 15 | 500 | |
average | 1 | 20 | 900 |
2 | 11 | 700 | |
3 | 4 | 500 |
Formerly coded AR-110-MAST