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57 mm Aluminum Footblock — Lockoff 57 mm Aluminum Footblock — Lockoff 57 mm Aluminum Footblock — Lockoff
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57 mm Black Magic®

57 mm Aluminum Footblock — Lockoff

Part No. 3221
$237.05  Not available on-line. Please contact your Harken dealer.
Sheave Ø (mm)57 mm
Sheave Ø (in)2 1/4 in
Maximum line Ø (mm)12 mm
Maximum line Ø (in)7/16 in
Maximum working load (kg)1134 kg
Maximum working load (lb)2500 lb

The entire line of Black Magic® AirBlocks® has been redesigned with a sleek new look. Their unique, performance-packed engineering remains exactly the same.

Carrying some of the highest loads imposed by running rigging, these strong, lightweight blocks feature Torlon® roller bearings housed in a center cage. Rollers stay parallel for low-friction efficiency. Sculpted hardcoat-anodized aluminum sideplates protect sideload ball bearings. Dissimilar metals are isolated to minimize corrosion. Blocks are easily disassembled with a single hex wrench.

Use footblocks to redirect lines on the deck. Footblocks with lockoffs temporarily secure sheets.

Either metric or imperial flathead fasteners may be used for mounting and are not exposed.

Sheave Ø (mm)57 mm
Sheave Ø (in)2 1/4 in
Length (mm)84 mm
Length (in)3 5/16 in
Height (mm)25 mm
Height (in)1 in
Weight (g)154 g
Weight (oz)5.44 oz
Maximum line Ø (mm)12 mm
Maximum line Ø (in)7/16 in
Maximum working load (kg)1134 kg
Maximum working load (lb)2500 lb
Breaking load (kg)2268 kg
Breaking load (lb)5000 lb
Number of fasteners
Fasteners (mm)6 FH mm
Fasteners (in)1/4 FH in
A (mm)7 mm
A (in)9/32 in
B (mm)23 mm
B (in)7/8 in
C (mm)52 mm
C (in)2 1/32 in
D (mm)16 mm
D (in)5/8 in
E (mm)58 mm
E (in)2 9/32 in
F (mm)84 mm
F (in)3 5/16 in
G (mm)12 mm
G (in)15/32 in
DWG: 3221.DWG (open/save)
DXF: 3221.DXF (open/save)
IGS: 3221.IGS (open/save)
EPS: 3221.eps (open/save)
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