crankshaft polishing Archives - Rebabbitting Bearing

Engine Bearings For Crankpin and Main Journal

Raj Shahani — Mon, 13 Apr 2026 09:14:46 +0000

Engine bearings manufactured from tri-metal for the crankpin and main journal of the crankshaft are supplied by RA Power Solutions.

We provide crankshaft grinding services, repair, and overall maintenance of auxiliary and main engines installed on vessels. We also extend these services to high-capacity power plants spread all over the world.

While standard-size bearings are readily available in stock with engine manufacturers, we have experienced that most of the time it is difficult to obtain tri-metal bearings for the crankpin and main journal of the crankshaft in undersized.

Undersized crankpin bearings

Crankpin Bearings For MAN & MAK Engines

White metal babbitt bearings

Undersized Bearings of Yanmar Diesel Engine

Requirement of Undersized Tri-Metal Bearings for Crankshaft

After grinding of the crankpin and main journal of the crankshaft, there is a requirement for undersized bearings, which are, in most cases, not readily available.

RA Power Solutions is the largest exporter of tri-metal bearings, mainly for diesel engines. We are listing below the names of a few popular engines and their models for which we maintain a ready stock of the bearings.

Sr No.	Description
Daihatsu 6DL-16 Standard Crankpin Diameter-120 mm
1	a) 2.50 mm Undersize Crankpin Bearing
	b) 3.00 mm Undersize Crankpin Bearing
	c) 4.00 mm Undersize Crankpin Bearing

MAN CME 5L 16/24 Standard Crankpin Diameter: 130 mm
2	a) 0.50 mm Undersized Crankpin Bearing
	b) 1.00 mm Undersized Crankpin Bearing
	c) 1.50 mm Undersized Crankpin Bearing
	d) 2.00 mm Undersized Crankpin Bearing
	e) 2.50 mm Undersized Crankpin Bearing

Yanmar Engine S 185L Standard Crankpin Diameter-140 mm
3	a) 0.80 mm Undersized Crankpin Bearing
	b) 1.20 mm Undersized Crankpin Bearing
	c) 1.60 mm Undersized Crankpin Bearing
	d) 2.00 mm Undersized Crankpin Bearing

Yanmar Engine 6N18AL-DN/DV Standard Crankpin Diameter: 145 mm
4	a) 0.40 mm Undersized Crankpin Bearing
	b) 0.80 mm Undersized Crankpin Bearing
	c) 1.20 mm Undersized Crankpin Bearing
	d) 1.60 mm Undersized Crankpin Bearing
	e) 2.00 mm Undersized Crankpin Bearing
	f) 2.40 mm Undersized Crankpin Bearing
	g) 2.80 mm Undersized Crankpin Bearing

Daihatsu 5DC-17 Standard Crankpin Diameter-145mm
5	a) 0.50 mm Undersized Crankpin Bearing
	b) 1.00 mm Undersized Crankpin Bearing
	c) 1.50 mm Undersized Crankpin Bearing
	d) 2.00 mm Undersized Crankpin Bearing
	e) 2.50 mm Undersize Crankpin Bearing
	f) 3.00 mm Undersize Crankpin Bearing
	g) 4.00 mm Undersize Crankpin Bearing

MAK 8M20 Standard Crankpin Diameter: 152 mm
6	a) Standard Undersized Crankpin Bearing
	b) 1.00 mm Undersized Crankpin Bearing
	c) 1.50 mm Undersized Crankpin Bearing
	d) 2.00 mm Undersized Crankpin Bearing

Daihatsu 5DK-20 Standard Crankpin Diameter-170mm
7	a) 0.50 mm Undersized Crankpin Bearing
	b) 1.00 mm Undersized Crankpin Bearing
	c) 1.50 mm Undersized Crankpin Bearing
	d) 2.00 mm Undersized Crankpin Bearing
	e) 2.50 mm Undersize Crankpin Bearing
	f) 3.00 mm Undersize Crankpin Bearing
	g) 3.50 mm Undersize Crankpin Bearing
	h) 4.00 mm Undersize Crankpin Bearing
	i) 5.00 mm Undersize Crankpin Bearing

MAN 6L 23/30H Standard Crankpin Diameter: 185 mm
8	Key Position 12.5 x 15.5
	a) 0.50 mm Undersized Crankpin Bearing
	b) 1.00 mm Undersized Crankpin Bearing
	c) 1.50 mm Undersized Crankpin Bearing
	d) 2.00 mm Undersized Crankpin Bearing
	e) 2.50 mm Undersized Crankpin Bearing
	f) 3.00 mm Undersized Crankpin Bearing
	g) 4.00 mm Undersized Crankpin Bearing
	h) 5.00 mm Undersized Crankpin Bearing

	Key Position 7.7 x 10.7
	a) 0.50 mm Undersized Crankpin Bearing
	b) 1.00 mm Undersized Crankpin Bearing
	c) 1.50 mm Undersized Crankpin Bearing
	d) 2.00 mm Undersized Crankpin Bearing
	e) 2.50 mm Undersized Crankpin Bearing
	f) 3.00 mm Undersized Crankpin Bearing
	g) 4.00 mm Undersized Crankpin Bearing
	h) 5.00 mm Undersized Crankpin Bearing

Allen Engine PVBCS 12 F Standard Crankpin diameter – 190.45 mm to 190.47 mm
9	a) 0.50 mm Undersized Crankpin Bearing
	b) 1.00 mm Undersized Crankpin Bearing

MAN 9ASL 25/30 Standard Crankpin Diameter-195 mm
10	a) 2.50 mm Undersize Crankpin Bearing
	b) 3.00 mm Undersize Crankpin Bearing
	c) 4.00 mm Undersize Crankpin Bearing

Gas Engine Deutz MWM TBG32V16 Standard Crankpin diameter 204.50 mm
11	a) 0.50 mm Undersized Crankpin Bearing

MAN 9L28/32 H Standard Crankpin Diameter-230 mm
12	a) 0.50 mm Undersized Crankpin Bearing
	b) 1.00 mm Undersized Crankpin Bearing
	c) 1.50 mm Undersized Crankpin Bearing
	d) 2.00 mm Undersized Crankpin Bearing
	e) 2.50 mm Undersize Crankpin Bearing
	f) 3.00 mm Undersize Crankpin Bearing

Daihatsu 8DKM-28 Standard Crankpin Diameter-235 mm
13	a) 0.50 mm Undersized Crankpin Bearing
	b) 1.00 mm Undersized Crankpin Bearing
	c) 1.50 mm Undersized Crankpin Bearing
	d) 2.00 mm Undersized Crankpin Bearing
	e) 2.50 mm Undersize Crankpin Bearing

Daihatsu 8DK-32 Standard Crankpin Diameter-250 mm
14	a) 0.50 mm Undersized Crankpin Bearing
	b) 1.00 mm Undersized Crankpin Bearing
	c) 1.50 mm Undersized Crankpin Bearing

White Metal Babbitt Bearings

We also manufacture Babbitt white metal bearings and undertake the repair of old, damaged bearings for different applications such as alternators, intermediate shafts, turbines, pumps, etc.

Main Journal Bearings Standard & Undersize

Diesel engine bearings supplier

Engine Bearing Manufacturers

Crankpin Bearing Suppliers

R A Power Solutions: Complete Services for Crankshafts and Engines

R A Power Solutions not only sells bearings but also offers a full range of services at your location or in their workshop, such as

Grinding the crankshaft in place
Crankshaft repair and reconditioning
Grinding and polishing of crankpins on site
Repairing engine blocks and stitching metal
Emergency breakdown services worldwide
Repair services for marine and diesel engines

Our advanced portable equipment and experienced technicians enable us to deliver onsite services without dismantling, helping industries reduce downtime and operational costs.

We work with clients all over the world, including big areas like Saudi Arabia, the United Arab Emirates, Qatar, Kuwait, Oman, and Bahrain. We make sure that our service is quick and dependable.

After crankshaft grinding, the undersized crankpin and main journal bearings are very important. With ready stock availability and integrated repair services, R A Power Solutions ensures quick turnaround and dependable performance for all types of engines.

For undersized crankpin and main journal bearing requirements, please email us at info@rapowersolutions.com or call +91-9582647131 or +91-9810012383.

The post Engine Bearings For Crankpin and Main Journal appeared first on Rebabbitting Bearing.

Insitu Crankshaft Repair | Onsite Crankshaft Grinding And Polishing | 47 Years Of Expertise

Raj — Fri, 18 Apr 2025 11:27:42 +0000

RA Power Solutions Pvt. Ltd. has offered in situ crankshaft repair and polishing services for over four decades. The crankshaft is the most important part for keeping the engine running properly. It is an essential component of engines in marine boats, power plants, and heavy machinery. However, when it becomes damaged or worn out, it can bring operations to a standstill, resulting in costly repairs and downtime. RA Power Solutions, a global pioneer in crankshaft maintenance, has introduced its breakthrough in situ crankshaft grinding technology to Bangladesh. This unique approach is changing the game for industries throughout the country.

With the insitu crankshaft grinding machine, our trained specialists can arrive at a site in the shortest amount of time and fix the crankshaft without removing it from the main engine.

Efficient crankshaft on the engine Restoration: 35 to 700 mm in diameter Grinding Accuracy

Since the crankshaft is the engine’s central component, it transforms reciprocating motion into the linear movement that powers the engine through the use of connecting rods. With the process, technology, and onsite crankshaft grinding equipment from RA Power Solutions, crankshaft repair is now feasible without removing the crankshaft from the engine. These machines range in size from 35 mm to 700 mm. Our technology can repair crankshafts up to 700 mm in diameter, allowing us to fix any crankshaft, regardless of its weight or length.

In general, the crankshaft has several applications, including diesel generators and marine engines. Typical areas of crankshaft applications are as follows:

Compressors
Power generators
Forging hammers
Pumps
Marine engines

RA Power’s Journal and Crankshaft Machining Advantages:

The vast experience of having repaired over 10,000 shafts on any size Main or Auxiliary engine

Specially designed crankshaft machining tooling for insitu reconditioning without dismantling the full engine, deployed all around the globe.

A large, global team of highly skilled machining technicians ensures a rapid, expert response anytime and anywhere.

The latest breed of inspection instruments is available to undertake hardness tests, MPI, surface roughness tests, dimensional inspection, etc.

Our crankshaft grinding machine weighs 1/3rd of our competitors, saving on freight costs.

Giving ship and power plant crews the tools they need to grind and fix crankshafts on site

Years of crankshaft grinding and polishing by RA Power Solutions, it is now possible to not only grind and polish the crankshaft onsite, but also to repair the crankshaft by ship or power plant crew.

For more information on in situ crankshaft grinding, onsite crankshaft grinding, crankshaft grinding, insitu crankshaft grinding repair, onsite crankshaft machining, and crankshaft machining in situ, crankpin bearings, bearings for MAN and MAK engines please contact info@rapowersolutions.com, rajshahani@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.

FAQs

1. What sizes of crankshafts can you repair onsite?

Customers often want to know the diameter range your equipment handles. RA Power’s insitu grinding is capable of servicing crankpins from 35 mm up to 700 mm (even 50–700 mm) without engine removal.

2. How much downtime and cost savings are involved?

One of the top concerns: how in-situ grinding cuts downtime and expense. By avoiding full engine disassembly and shipping, companies save significantly on labor, transport, and workshop costs.

3. What precision and finish can you achieve?

Customers ask if the onsite process meets OEM specifications. The portable machines deliver precision within 10–25 µm and achieve surface finishes (Ra) that align with OEM standards.

4. Can you repair crankshafts while the engine is in operation or at sea?

A common need in marine and power-plant contexts. Yes—insitu grinding can be done on-vessel (even underway) or at power plants, offering portable, global 24/7 service.

5. What inspection and quality assurance processes do you use?

Customers want confirmation of quality control. Services typically include MPI/crack detection, hardness testing, surface roughness measurement, dimensional checks, vibration testing, ensuring journals are restored to spec.

The post Insitu Crankshaft Repair | Onsite Crankshaft Grinding And Polishing | 47 Years Of Expertise appeared first on Rebabbitting Bearing.

Consequences Of Hand Polishing Of Crankshaft and Benefits Of Crankshaft Polishing Machine

Raj — Mon, 11 Feb 2019 20:12:40 +0000

Manufacturers of high capacity diesel engines are maintaining close tolerances in terms of taper and ovality of crankpin and main journal diameter of the crankshaft. The maintenance of close tolerances and high surface finish results in the generation of more power, longer life of crankshaft and bearing, less noise level, low vibration, friction, and better fuel efficiency. RA Power Solutions has been working on crankshafts of marine engines and engines used for various applications with diameters ranging from 30 mm to 700 mm.

On Site Crankshaft Grinding

What Goes Wrong with Hand Polishing

Based on RA Power Solutions’ decades of experience, here are the main drawbacks:

Bearing line marks and pitting remain
Minor surface damage, like line marks (from bearings) and pitting, is not removed completely by hand polishing. These defects undermine surface integrity and can lead to premature wear.
Taper and ovality get worse, not better
Crankpin and main journals often have tight tolerances for taper and ovality (i.e., deviation from perfect cylindricity or uniform diameter). Hand polishing cannot correct these and often makes them worse.
Surface finish suffers
Engine and bearing manuals usually specify key metrics like surface roughness (e.g., Ra values). Hand polishing can’t ensure you reach those finishes reliably.

What the OEMs / Manuals Require

To deliver optimal performance, crankshaft components must often meet:

Taper & ovality between 0.02 mm to 0.05 mm, depending on diameter.
Surface finish of Ra < 0.25 (unit depends on the standard, usually microns).

These are very tight tolerances, difficult to consistently achieve with hand methods.

Onsite Grinding and Polishing Machines: Key Benefits

RA Power Solutions has developed (and field-tested) portable onsite machines with capabilities for diameters from ~30 mm up to ~700 mm. Here are the advantages they bring:

Benefit	What It Means in Practice
Precision	Grinding + polishing deliver accurate, measurable correction of taper, ovality, surface finish.
Time Saved	Because you don’t need to remove the crankshaft—machine can be inserted via inspection window. Less downtime.
Longer engine / bearing life	Better surfaces, fewer defects mean less friction, wear, vibrations etc.
Cost savings	Avoid repeated failures or having to send the crankshaft out; avoid hiring expensive overseas services.
Transferable skill	Once you have the machine, your own technicians can be trained to use it—so dependence on outside vendors reduces.

Portable Crankshaft Grinding Machine by RA Power Solutions:

RA Power Solutions has introduced a portable, lightweight, onsite crankshaft grinding and polishing machine which is capable of grinding and polishing diameters ranging from 30 mm to 700mm. The onsite crankshaft grinding machine is revolutionary. You can insert this portable equipment through the inspection window of the engine block. There is no requirement for the removal of the crankshaft from the engine block.

RA Power Solutions specializes in crankshaft polishing, offering high-quality services to improve the performance and longevity of crankshafts. our skilled technicians utilize state-of-the-art equipment and cutting-edge techniques for precise and efficient crankshaft polishing. The use of a dedicated crankshaft polisher ensures that the polishing process is done with utmost precision and consistency.

For more information on Onsite Crankshaft Polishing, Crankshaft Grinding please email us at rajshahani@rapowersolutions.com, or info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.

The post Consequences Of Hand Polishing Of Crankshaft and Benefits Of Crankshaft Polishing Machine appeared first on Rebabbitting Bearing.