Sparcraft I Masts

Sparcraft IM Mast Sections are primarily Cruising Sections designed as direct replacements for discontinued Isomat Mast Sections, but without an integral Spinnaker Track. Except for the integral Spinnaker Track, the Sections are identical, and all parts (except for Spinnaker Cars) are interchangeable. Though Sparcraft uses a number of common components in their Spar Assemblies, many Mast Parts are specific to a particular Mast Section. For these parts you must determine which Mast Section you have by measuring its' maximum Outside Dimensions. Click on individual Mast Sections, below, to see hardware commonly used with those Sections. For common replacement Mast Parts, See Sparcraft Mast Components, below. For complete Mast Assemblies, contact us with details. See also Sparcraft Booms, and Sparcraft Spreaders. See also, Isomat Mast Sections, other Sparcraft Mast Sections.

Sparcraft IM-137 Mast Measurements (OD): 5 3/4" x 3 7/8" (145mm x 98mm) Wall Thickness (minimum): 2.45mm Weight/M: 3.1kg. - Weight/ft.: 2.08 lbs. Moments of inertia: Ixx = 7.35", Iyy = 3.29" Moments of inertia: Ixx = 306cm4, Iyy = 137cm4 Circumference: 16" Sail slides: 8mm boltrope or round slides, Soro BRS5 Sail slides: 16mm flat slides, Soro FP17 Alloy: 6005-T6 Standard Mast Lengths: 3.3M Replaces NG-28L Common Mast usage: Compac 27; Fantasia; Hurley 800;
Sparcraft IM-180 Mast Measurements (OD): 6 1/4" x 4 1/16" (159mm x 104mm) Wall Thickness (minimum): 2.6mm Weight/M: 3.2kg. - Weight/ft.: 2.15 lbs. Moments of inertia: Ixx = 9.27", Iyy = 3.82" Moments of inertia: Ixx = 386cm4, Iyy = 159cm4 Circumference: 17 1/4" (438mm) Sail slides: 8mm boltrope or round slides, Soro BRS5 Sail slides: 16mm flat slides, Soro FP17 Alloy: 6005-T6 Standard Mast Lengths: 12.18M, 14.65M (48' 1") Replaces Isomat NG-31 Common Mast usage: Albin Alpha; Hanse 301; J/92S;* Sunbeam 30.2; X 302 mk.2;
Sparcraft IM-260 Mast Measurements (OD): 6 11/16" x 4 1/2" (170mm x 115mm) Wall Thickness (minimum): 3.1mm Weight/M: 4.2kg. - Weight/ft.: 2.82 lbs. Moments of inertia: Ixx = 14.05", Iyy = 6.18" Moments of inertia: Ixx = 585cm4, Iyy = 257cm4 Circumference: 18 1/2" (470mm) Sail slides: 8mm boltrope or round slugs, Soro BRS5 Sail slides: 23mm flat slides, or 16mm, Soro FP17 Alloy: 6005-T6 Standard Mast Lengths: 13.7M, 14.81M, 16.1M (52' 10") Replaces Isomat NG-37 Common Mast usage: Beneteau Oceanis 311; Gemini 105; J/92, J/97; Hunter 310, 340, 360; Pacific Seacraft; Seaward 30, 32;
Sparcraft IM-330 Mast Measurements (OD): 7 1/16" x 4 3/4" (180mm x 120mm) Wall Thickness (minimum): 3.2mm Weight/M: 4.8kg. - Weight/ft.: 3.23 lbs. Moments of inertia: Ixx = 18.21", Iyy = 7.98" Moments of inertia: Ixx = 742cm4, Iyy = 325cm4 Circumference: 19 3/4" (500mm) Sail slides: 8mm boltrope or round slugs, Soro BRS5 Sail slides: 23mm flat slides, or 16mm, Soro FP17 Alloy: 6005-T6 Standard Mast Lengths: 41' - 59' (12.5 - 18M) Replaces Isomat NG-46 Common Mast usage: Bavaria 340; Beneteau First 32, 33.7; Oceanis 321, 361; Chatham 330; Drop 26; Gibsea 106, 372; Hunter 380; Jeanneau Sun Shine, Sun Odyssey 35; and many More.*
Sparcraft IM-1170 Mast Measurements (OD): 9 3/4" x 6 3/4" (247mm x 172mm) Wall Thickness (minimum): 4mm Weight/M: 8.98kg. - Weight/ft.: 6.01 lbs. Moments of inertia: Ixx = 59.59", Iyy = 27.87" Moments of inertia: Ixx = 2480cm4, Iyy = 1160cm4 Circumference: 26 3/4" (680mm) Sail slides: 15/16" flat slides, MM#8 Alloy: 6005-T6 Standard Mast Lengths: 19M Replaces Isomat NG-86 Common Mast usage: Lagoon 380;
Sparcraft IM-1630 Mast Measurements (OD): 11 1/8" x 7 3/16" (283mm x 182mm) Wall Thickness (minimum): 4.6mm Weight/M: 10.7kg. - Weight/ft.: 7.17 lbs. Moments of inertia: Ixx = 93.34", Iyy = 39.16" Moments of inertia: Ixx = 3885cm4, Iyy = 1630cm4 Circumference: 30" (762mm) Sail slides: 15/16" flat slides, MM#8 Alloy: 6005-T6 Standard Mast Lengths: 19.7M, Replaces Isomat NG-105 Common Mast usage: Lagoon 420, 440; Prout 45;

IM Mast Components

Sparcraft uses a number of common components in their Spar Assemblies. Parts that are common to a variety of IM Masts are listed below. Many Mast Parts, however, are specific to individual, or a small number of Mast Sections, and are listed under those particular Mast Sections.

For Parts not listed below, determine which Mast Section you have (by measuring).
Click on individual Mast Sections (above) to see hardware commonly used with those Masts.

Sheaves & Rollers
External Masthead Spinnaker Cranes
External Spinnaker Halyard Blocks
Masthead Stemball / Eye Adapters
Halyard Fairleads / Eyes / Spectacles
Forestay/Staysail Stay Tangs
Fractional Jib Boxes
Exit Blocks
Spreaders

Spinnaker Cars for T-Track
Spinnaker Cars for Ball-Bearing Tracks
Halyard Exit Plates
Spar Cleats
Welded Mast Base Exit Boxes
Vang Brackets & Vang Toggles
Solid Vangs
Mast Base Turning Blocks & Attachments
Mast Wedges
Deck Tie-down Turnbuckles

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