2025 Ronstan Marine Catalogue - Catalog - Page 57
KEELBOAT BLOCKS
Series 60 Core
55
RF64500
RF64520
RF64503
RF64523
20mm
3/4”
20mm
3/4”
RF64140
RF64108A
RF64251
RF64151
14mm
(9/16”)
RF64108A suits 14mm (9/16”) mast
collar post (not supplied)
2 x 8mm (5/16”)
RF617A
6mm (1/4”) pin suits single
& 昀椀ddle shackle head blocks
RF64520 & RF64523 cleating angle is adjustable and
are fitted with a high performance C-Cleat™ and
fairlead for secure and easy cleating.
Fiddle blocks incorporate an integrated becket
through the hub of the lower sheave, and are ideal
for creating simple vang and mainsheet systems up
to 4:1 on boats to 12m (40ft).
RF64503 & RF64523 features a versatile trunnion
snap shackle with rotation and
side-to-side articulation.
2 x 8mm (5/16”)
4 x 6mm (1/4”)
RF64108A mast base block has a removable clevis
pin to suit a 14mm (9/16”) wide mast collar post.*
Shackle, post & hub: Grade 316
stainless steel.
Universal head can be fixed at 0° or 90° or left free
to swivel, by using a 2.5mm hex key.
Pins: Grade 2205 stainless steel
(RF64108, RF64108A, RF64202).
BB sheaves: UV stabilised acetal.
Cheek plates: Aluminium alloy.
Snap shackle & pad eye: Grade 15-5PH
investment cast stainless steel.
Ball bearings: High compression strength acetal.
Cleat: Fibre reinforced composite.
PRODUCT No.
DESCRIPTION
SHEAVE MAX.
DIAM. ROPE
mm
mm
Ball Bearing
RF64108A
RF64500
RF64503
RF64520
RF64523
RF64140
RF64151
RF64251
Mast base block, clevis pin head
Fiddle block, universal head
Fiddle block, snap shackle head
Fiddle block, cleat, universal head
Fiddle block, cleat, snap shackle head
Stand-up block, swivelling
Foot block, single
Foot block, double
60
60 + 30
60 + 30
60 + 30
60 + 30
60
60
60
12
12
12
12
12
12
12
12
MAX.
WIRE
mm
-
PIN
DIAM. M.W.L.
mm
kg
8
6
6
-
1000*1
1000
1000
525*3
525*3
1000
1000
1000*2
B.L.
kg
WEIGHT
g
SHEAVE
DIAM.
in
MAX.
ROPE
in
MAX.
WIRE
in
2000*1
2000
2000
2000
2000
2000
2000
2000*2
182
355
405
490
540
372
180
370
2 3/8
2 3/8+ 1 3/16
2 3/8+ 1 3/16
2 3/8+ 1 3/16
2 3/8+ 1 3/16
2 3/8
2 3/8
2 3/8
1/2
1/2
1/2
1/2
1/2
1/2
1/2
1/2
-
*1 Full block rated load can only be achieved with uniformly distributed load across full length of clevis pin. i.e. 14mm (9/16”) diameter mast collar post or 14mm (9/16”) wide mast collar plate/tang.
*2 Total block load. Maximum load on top sheave not to exceed 50% of total block load.
*3 MWL based on maximum allowable line load through cleat of 175kg (385lb), 3:1 purchase.
PIN
DIAM. M.W.L.
in
lb
5/16
1/4
1/4
-
2200*1
2200
2200
1160*3
1160*3
2200
2200
2200*2
B.L.
lb
WEIGHT
oz
4410*1
4410
4410
4410
4410
4410
4410
4410*2
6.4
12.5
14.2
17.3
19.0
13.2
6.4
13.1
