TWIN-PETP roller bearings type 6S

The table below shows all key dimensions of the 6S series TWIN-PETP roller bearings in GRP tube. The measurement D is the outside diameter of the GRP tube.

PART NO. Bottom Bearing dia. "db" Top Bearing dia. "dt" TUBE dia. "D" HEIGHT "H" *2 WEIGHT *1 WORKING LOAD (max)
6S030 - 6S049 30 to 49 mm 30 to 49 mm 90 mm max. 1000 mm 1.9 kg 1300-1800 kg
6S050 - 6S069 50 to 69 mm 30 to 69 mm 110 mm max. 1000 mm 3.1 kg 2500-3200 kg
6S070 - 6S089 70 to 89 mm 50 to 89 mm 130 mm max. 1000 mm 3.6 kg 4200-4800 kg
6S090 - 6S109 90 to 109 mm 50 to 109 mm 150 mm max. 1000 mm 4.5 kg 4900-6200 kg
6S110 - 6S139 110 to 139 mm 70 to 139 mm 180 mm max. 1000 mm 5.7 kg 6300-8400 kg
6S140 - 6S169 140 to 169 mm 90 to 169 mm 210 mm max. 1000 mm 6.3 kg 8400-9500 kg
*1: Weight taken with a 800 mm tube.
*2: Longer tubes are available at a surcharge.

PART NO. Bottom Bearing dia. "db" Top Bearing dia. "dt" TUBE dia. "D" HEIGHT "H" *2 WEIGHT *1 WORKING LOAD (max)
6S030 - 6S049 30 to 49 mm 30 to 49 mm 90 mm max. 1000 mm 1.9 kg 1300-1800 kg
6S050 - 6S069 50 to 69 mm 30 to 69 mm 110 mm max. 1000 mm 3.1 kg 2500-3200 kg
6S070 - 6S089 70 to 89 mm 50 to 89 mm 130 mm max. 1000 mm 3.6 kg 4200-4800 kg
6S090 - 6S109 90 to 109 mm 50 to 109 mm 150 mm max. 1000 mm 4.5 kg 4900-6200 kg
6S110 - 6S139 110 to 139 mm 70 to 139 mm 180 mm max. 1000 mm 5.7 kg 6300-8400 kg
6S140 - 6S169 140 to 169 mm 90 to 169 mm 210 mm max. 1000 mm 6.3 kg 8400-9500 kg
*1: Weight taken with a 800 mm tube.
*2: Longer tubes are available at a surcharge.


6S specification form:

Please click the left icon to open the 6S specification form in Adobe PDF. You can fill in the gray field with the correct info and tick the appropriate boxes. This form is required to guarantee a correct production of your bearing.


The applications for the 6S series bearing:
The 6S series bearings are developed as a more affordable alternative on the 6D bearings. The bearing is made of PETP (also known as Arnite, Ertalyte, Sustodur & Ultradur) in a GRP tube, allowing it to be laminated directly into the hull. It’s primarily meant to be used on tiller steered boats, but could be used on wheel steered boats if the tiller arm / quadrant is above the top bearing.

Installation of JEFA Marine composite bearings in female moulded hulls:

  1. The GRP tube of the 6T bearing is delivered with a shiny resin surface. To achieve a good bonding to the hull it’s important to roughen the outside surface with a grinder or sanding machine so no shiny surface is left. This should be done just prior to laminating the bearing to the hull.
  2. Secure the bearing-housing in it’s place in the hull. The bearing should be jigged in place firmly so that it won’t alter position when worked during lamination and remove the bearing ball to make sure no resin will enter the rollers.
  3. Tape a bag over the top of the bearing to cover the entire bearing neatly.
  4. Gel-coat the hull.
  5. Just prior to lamination, carefully remove the bag.
  6. Laminate the hull making sure that the laminate runs up the side of the bearing in full thickness. It can be tapered down over a 100 mm span beginning just above the self aligning bearing in the bearing tube.
  7. There should always be a skin joint around the bearing that is at least three times the bearing housings measurement in diameter, and the laminate should have a minimum thickness of 1.5x(1.8+(LWL/1.8), this thickness is not including the foam ram mentioned bellow.
  8. When laminating the hull the first 10% of the prescribed laminate should be laid directly into the hull to bearing housing joint. On top of this “outer skin” there should be a foam ramp or fillet (minimum 200 kilo/m3 density), which encircles the bearing housing. The remainder of the laminate runs up over the foam ramp.
  9. When the hull is de-moulded and the deck bearing is ready for installation the bearing ball can be inserted into the two slots in the bearing housing and rotated into place.
Please remember that these guidelines represent good practice, however all structural components of a sailing vessel should be engineered by a qualified engineer for the actual case. JEFA MARINE takes no responsibility for any structural failures which might result from the use of these guidelines.
 

6S examples:


Fitting tiller stops to the 6D bearings:

The 6D series bearings standard have no tiller stop arrangement . By adding a flange with stops which can be bolted to the deck, additional tiller stops can be added. There is one flange to work with our tiller heads Ø25 mm to Ø40 (6SP035STP) and one to work with our 50 mm tiller head (6SP050STP).


6SP035STP dimensions:

6SP050STP dimensions:

TILLER STOPS

PART NO. DISCRIPTION corresponding tiller heads
6SP035STP Tiller stop up to 40 mm shaft 25 - 40 mm
6SP050STP Tiller stop up to 50 mm shaft 50 mm