Tri Metal Bearings in Stock — Including the Sizes Most Suppliers Can’t Find
Most of the calls we get aren’t for common bearing sizes. These enquiries often come from superintendents or purchasing agents who have already been turned away by other suppliers. The engine may be older, the OEM may have discontinued the specification, or the bearing size may be rare. We bridge that gap by stocking tri-metal bearings in a wide range of specifications, including hard-to-find sizes. We regularly ship overseas to help keep vessels operating without unnecessary delays.
Why Certain Specifications Are Hard to Find
A tri-metal bearing — steel back, copper-lead or bronze intermediate layer, lead-tin or babbitt overlay — sounds like a standard item until you’re trying to match one to a specific crankshaft journal diameter, a discontinued engine model, or a size that falls outside current OEM production runs. Older tonnage and legacy engine types are the usual culprits. The manufacturer may have moved to a newer engine series, but the vessel still needs bearings matching the original wall thickness, crush height, and oil groove geometry. When these sizes are no longer available, downtime can increase quickly, especially when a vessel is alongside and waiting for parts to complete the repair.
What We Keep in Stock – RA Power Solutions
RA Power Solutions carries tri-metal bearings in a wide range of specifications, including undersized shells for crankshaft regrinding. Bearings are supplied in standard undersize increments or machined to as-reground dimensions when required. Wall thickness, ovality, and taper are maintained within OEM tolerances, including for rare specifications. If your crankshaft has been reground, we can supply bearings based on the actual measured journal diameter rather than a nominal size.
Crankpin Bearing Sizes Available for Major Marine Diesel Engines
The following tables provide an overview of standard and undersize crankpin bearing options available for selected YANMAR, MAN, Daihatsu, and MAK marine diesel engine models, along with their corresponding stock quantities.
( New Stock Available)
YANMAR 6N18AL-DN/DV – Available Crankpin Bearing Sizes
For the YANMAR 6N18AL-DN/DV diesel engine, the standard crankpin diameter is 145 mm. The following undersize bearing sizes are available, with quantities maintained in stock as listed below.
| Crankpin Bearing Size | Stock Available |
| 0.40 mm undersize | 8 pairs |
| 0.80 mm undersize | 10 pairs |
| 1.20 mm undersize | 8 pairs |
| 1.60 mm undersize | 8 pairs |
| 2.00 mm undersize | 10 pairs |
| 2.40 mm undersize | 4 pairs |
| 2.80 mm undersize | 4 pairs |
MAN CME 5L 16/24 – Bearing Sizes for 130 mm Crankpins
The MAN CME 5L 16/24 engine has a 130 mm standard crankpin diameter. Our available bearing inventory covers both standard and progressively undersized crankpin dimensions.
| Bearing Specification | Quantity Available |
| Standard size | 6 pairs |
| 0.50 mm undersize | 6 pairs |
| 1.00 mm undersize | 10 pairs |
| 1.50 mm undersize | 6 pairs |
| 2.00 mm undersize | 7 pairs |
| 2.50 mm undersize | 7 pairs |
Daihatsu 5DK20 – Crankpin Bearings in Multiple Undersizes
For the Daihatsu 5DK20, the standard crankpin diameter is 170 mm. Several bearing dimensions are available to accommodate different crankshaft regrinding requirements.
| Bearing Size | Available Stock |
| Standard size | 6 pairs |
| 0.50 mm undersize | 6 pairs |
| 1.00 mm undersize | 6 pairs |
| 1.50 mm undersize | 6 pairs |
| 2.00 mm undersize | 6 pairs |
| 2.50 mm undersize | 4 pairs |
| 3.00 mm undersize | 2 pairs |
| 3.50 mm undersize | 2 pairs |
| 4.00 mm undersize | 2 pairs |
| 5.00 mm undersize | 2 pairs |
Daihatsu 5DC-17 – Replacement Bearing Sizes for 145 mm Crankpins
The Daihatsu 5DC-17 uses crankpins with a 145 mm standard diameter. The available inventory includes multiple undersize options.
| Crankpin Size | Pairs in Stock |
| 0.50 mm undersize | 7 pairs |
| 1.00 mm undersize | 6 pairs |
| 1.50 mm undersize | 20 pairs |
| 2.00 mm undersize | 7 pairs |
| 2.50 mm undersize | 7 pairs |
| 3.00 mm undersize | 6 pairs |
| 4.00 mm undersize | 6 pairs |
YANMAR-S 185L – Bearing Inventory for 140 mm Crankpins
The standard crankpin diameter for the YANMAR-S 185L is 140 mm. The following undersize bearing dimensions are currently represented in the available inventory.
| Undersize Bearing Dimension | Quantity |
| 0.80 mm undersize | 3 pairs |
| 1.20 mm undersize | 3 pairs |
| 1.60 mm undersize | 5 pairs |
| 2.00 mm undersize | 5 pairs |
Daihatsu 8DKM28 – Crankpin Bearing Options for 235 mm Diameter
The Daihatsu 8DKM28 has a 235 mm standard crankpin diameter. Both standard and undersize bearing configurations are available in the following quantities.
| Bearing Configuration | Stock Quantity |
| Standard size | 3 pairs |
| 0.50 mm undersize | 4 pairs |
| 1.00 mm undersize | 3 pairs |
| 1.50 mm undersize | 2 pairs |
| 2.00 mm undersize | 2 pairs |
| 2.50 mm undersize | 2 pairs |
Daihatsu 6DL-16 – Undersized Bearings for 120 mm Crankpins
For the Daihatsu 6DL-16, the standard crankpin diameter is 120 mm. The available stock covers the following reconditioning sizes.
| Available Bearing Undersize | Pairs Available |
| 2.00 mm undersize | 3 pairs |
| 2.50 mm undersize | 3 pairs |
| 3.00 mm undersize | 3 pairs |
MAK 8M20 – Bearing Stock for 152 mm Standard Crankpins
The MAK 8M20 has a 152 mm standard crankpin diameter. The bearing sizes currently available are listed below.
| Bearing Dimension | Stock on Hand |
| Standard size | 2 pairs |
| 1.00 mm undersize | 1 pair |
| 1.50 mm undersize | 2 pairs |
| 2.00 mm undersize | 2 pairs |
MAN 9ASL 25/30 – Available Bearings for 195 mm Crankpins
The MAN 9ASL 25/30 has a 195 mm standard crankpin diameter. The following undersized bearing options are available.
| Crankpin Bearing Size | Quantity in Stock |
| 2.50 mm undersize | 1 pair |
| 3.00 mm undersize | 2 pairs |
| 4.00 mm undersize | 2 pairs |
MAN 6L 23/30 H – Bearing Sizes by Key Position
The MAN 6L 23/30 H has a standard crankpin diameter of 185 mm. Bearing availability differs according to the key-position configuration, so the two configurations are listed separately.
Key Position: 12.5 × 15.5 mm
| Bearing Undersize | Available Quantity |
| 0.50 mm | 6 pairs |
| 1.00 mm | 4 pairs |
| 1.50 mm | 3 pairs |
| 2.00 mm | 3 pairs |
| 3.00 mm | 3 pairs |
| 4.00 mm | 3 pairs |
| 5.00 mm | 3 pairs |
Key Position: 7.7 × 10.7 mm
| Bearing Undersize | Available Quantity |
| 0.50 mm | 1 pair |
| 1.00 mm | 4 pairs |
| 1.50 mm | 3 pairs |
| 2.00 mm | 5 pairs |
| 2.50 mm | 6 pairs |
| 3.00 mm | 3 pairs |
| 4.00 mm | 3 pairs |
| 5.00 mm | 3 pairs |
Shipping Overseas, On Vessel Timelines
Supplying overseas isn’t just a matter of having stock — it’s about getting the right shell to the right port before the vessel needs to sail. We coordinate documentation upfront, including material certificates and dimensional inspection records, so there’s no delay at the receiving end if a class surveyor from DNV, ABS, or Lloyd’s needs to sight the paperwork during a periodic survey or before the vessel leaves drydock. We’ve shipped into ports across multiple regions on tight windows, and we structure the process so the bearing is ready to install the moment it clears customs, not sitting in a queue waiting on missing documents.
Nearly Five Decades of Sourcing the Hard-to-Find
We’ve been manufacturing and supplying tri metal bearings for marine and industrial engines for close to fifty years, and a good part of that experience is in tracking down specifications that have effectively gone out of production elsewhere. If you’re chasing a size that nobody else seems to carry, it’s worth checking with us before you assume it doesn’t exist — there’s a reasonable chance it’s already sitting in our stock, ready to ship.
Need Crankpin Bearings for MAK, MAN, YANMAR, or Daihatsu Engines?
For information on available standard and undersize crankpin bearings, contact RA Power Solutions. Share your engine model, crankpin diameter, and required undersize, and our team can confirm the suitable bearing size and availability.
Email: rajshahani@rapowersolutions.com | info@rapowersolutions.com
Phone: +91-9582647131 | +91-9810012383
